OPINION OF ADVOCATE GENERAL

SZPUNAR

delivered on 20 November 2014 ( 1 )

Case C‑533/13

Auto- ja Kuljetusalan Työntekijäliitto AKT ry

v

Öljytuote ry,

Shell Aviation Finland Oy

(Request for a preliminary ruling from the työtuomioistuin (Finland))

‛Temporary agency work — Directive 2008/104/EC — Article 4, paragraph 1 — Prohibitions or restrictions on the use of temporary agency work — Charter of Fundamental Rights of the European Union — Article 28 — Right of collective bargaining and action — Review of the compatibility with EU law of a clause in a collective agreement — Role of the national courts — ‘Horizontal’ dispute’

I – Introduction

1. The present case gives the Court an opportunity to interpret, for the first time, Directive 2008/104/EC on temporary agency work. ( 2 )

2. An action has been brought before the työtuomioistuin (Finnish Labour Court) by the Finnish transport workers’ union, seeking a decision finding that an undertaking in the transport sector and an employers’ association have infringed a clause in the applicable collective agreement, in particular, a clause relating to the use of temporary agency work. The Finnish court questions whether the clause in question constitutes an unjustified restriction on the use of temporary agency workers which is incompatible with Article 4(1) of Directive 2008/104 and whether it should therefore be disapplied.

3. The dispute in the main proceedings touches on certain systemic aspects of EU law. First, it requires a balance to be struck between EU social law and the principle of the freedom to provide services. Secondly, the Court may find it necessary to rule on the direct effect of Directive 2008/104 in the context of a ‘horizontal’ dispute between an undertaking and a trade union.

II – Legal framework

A – EU law

1. The Charter of Fundamental Rights of the European Union

4. Article 28 of the Charter of Fundamental Rights of the European Union (‘the Charter’), entitled ‘Right of collective bargaining and action’, provides: ‘Workers and employers, or their respective organisations, have, in accordance with [EU] law and national laws and practices, the right to negotiate and conclude collective agreements at the appropriate levels and, in cases of conflicts of interest, to take collective action to defend their interests, including strike action.’

2. Directive 2008/104

5. Article 4 of Directive 2008/104, entitled ‘Review of restrictions or prohibitions’, provides: ‘1. Prohibitions or restrictions on the use of temporary agency work shall be justified only on grounds of general interest relating in particular to the protection of temporary agency workers, the requirements of health and safety at work or the need to ensure that the labour market functions properly and abuses are prevented. 2. By 5 December 2011, Member States shall, after consulting the social partners in accordance with national legislation, collective agreements and practices, review any restrictions or prohibitions on the use of temporary agency work in order to verify whether they are justified on the grounds mentioned in paragraph 1. 3. If such restrictions or prohibitions are laid down by collective agreements, the review referred to in paragraph 2 may be carried out by the social partners who have negotiated the relevant agreement. … 5. The Member States shall inform the Commission of the results of the review referred to in paragraphs 2 and 3 by 5 December 2011.’

B – Finnish law

1. Legislation

6. Directive 2008/104 was transposed into Finish law by the amendment of Law 55/2001 on employment contracts (työsopimuslaki 55/2001) and Law 1146/1999 on posted workers (lähetetyistä työntekijöistä annettu laki 1146/1999).

7. As the national court points out, it is apparent from the explanatory memorandum to the draft amending law that the Finnish Government considered the obligation of review referred to in Article 4 of Directive 2008/104 to be a specific administrative requirement to review restrictions and prohibition on the use of temporary agency work and to inform the Commission of the outcome of that review. As the national court emphasises, according to the draft law, Article 4 does not require the Member States to amend their legislation, even in the event that a restriction on the use of temporary agency work cannot be justified on grounds of general interest.

8. On 29 November 2011, the Finnish Government informed the Commission of the outcome of the review conducted pursuant to Article 4(2) and (3) of Directive 2008/104.

2. Collective agreements

9. Point 8(3) of the general collective agreement concluded in 1997 between central organisations representing respectively employers and trade unions ( 3 ) stipulates: ‘Undertakings shall restrict the use of temporary agency workers to dealing with peaks of work or to the performance of other tasks of limited duration or of a specific nature which, for reasons of urgency or because of their limited duration or skill requirements or the use of special tools or other similar reasons, they cannot have performed by their own staff. The use of temporary workers is an unfair practice if the temporary agency workers employed by undertakings using external workers carry out the undertaking’s usual work alongside the undertaking’s permanent workers under the same management and for a long period of time. …’

10. The collective agreement for the tanker and oil products sector (‘the sectoral agreement’) contains a similar provision in Paragraph 29(1) thereof.

III – The dispute in the main proceedings

11. Auto- ja Kuljetusalan Työntekijäliitto AKT ry (‘AKT’) is the trade union which represents, inter alia, employees in the tanker and oil products sector.

12. The company Shell Aviation Finland Oy (‘Shell’) delivers fuel to 18 airports established in Finland. It is a member of the employers’ association in the fuels sector, Öljytuote ry (‘Öljytuote’).

13. AKT has sought an order from the referring court requiring Öljytuote and Shell to pay the fine provided for in Article 7 of Law 36/1946 on collective agreements (työoehtosopimuslaki 36/1946) on the ground of infringement of Paragraph 29(1) of the sectoral agreement. In its action, AKT argues that, since 2008, Shell has regularly employed temporary staff, on a considerable scale, to carry out tasks identical to those carried out by its own workers. That use of temporary workers is, according to AKT, an unfair practice within the meaning of the provision of the sectoral agreement at issue.

14. The defendants contend that the use of temporary agency workers was justified by legitimate reasons, since it was done, essentially, to replace workers during periods of annual leave and sick leave. They also argue that Paragraph 29(1) of the sectoral agreement contains a restriction that cannot be justified by the reasons referred to in Article 4(1) of Directive 2008/104. According to the defendants, the national court must disapply any provisions of collective agreements that are contrary to Directive 2008/104.

15. The national court states that, although the scope of the obligation imposed on the Member States by Article 4 of Directive 2008/104 raises doubts, the provision may be interpreted as imposing on the Member States an obligation to ensure that their legal systems contain no unjustified restrictions or prohibitions relating to temporary agency work. According to the national court, Paragraph 29(1) of the sectoral agreement follows a different approach from that defined by Directive 2008/104, inasmuch as it prohibits the employment of temporary agency workers except in certain specific cases, in order to protect the permanent workers of undertakings.

16. Furthermore, the national court is unsure as to the consequences to be drawn from the possible incompatibility of a national provision with Directive 2008/104 in a case such as that in the main proceedings, which is a dispute between individuals.

IV – The questions referred and the procedure before the Court

17. It is in that context that the työtuomioistuin decided to stay proceedings and to refer the following questions to the Court for a preliminary ruling: ‘(1) Is Article 4(1) of … Directive [2008/104] to be interpreted as imposing on national authorities, including the courts, a permanent obligation to ensure, by the means available to them, that no statutory provisions or clauses in national collective agreements exist that are contrary to the rules laid down by the directive or that, if such provisions or clauses exist, they are not applied? (2) Is Article 4(1) of … Directive [2008/104] to be interpreted as precluding national rules pursuant to which the use of temporary labour is permitted only in certain specific cases, such as to deal with peaks of work or to perform tasks which an undertaking cannot have its own employees perform? May the employment of temporary agency workers for a long period of time to carry out an undertaking’s usual work alongside the undertaking’s own employees be characterised as an unlawful use of temporary agency work? (3) If national rules are found to be contrary to … Directive [2008/104], what means are available to the courts to achieve the objectives of the directive in the event that the rules at issue are contained in a collective agreement that governs relationships between individuals?’

18. The order for reference of 4 October 2013 was lodged at the Court Registry on 9 October 2013. Written observations were submitted by AKT, Öljytuote and Shell, the Finnish, German, French, Hungarian, Polish, Swedish and Norwegian Governments, and by the Commission.

19. Those parties and entities, with the exception of the French, Hungarian and Polish Governments, also attended the hearing on 9 September 2014.

V – Analysis

20. The questions referred by the national court raise three issues regarding the interpretation of Article 4(1) of Directive 2008/104: — first, the scope of the obligations imposed by that provision on the Member States; — secondly, the possibility of justifying, for the purposes of that provision, the restrictions on the use of temporary agency work laid down in the sectoral agreement, and — thirdly, whether the provision of the directive in question may be relied on in disputes between individuals.

21. I shall address these issues in that order.

A – The scope of the obligations arising from Article 4(1) of Directive 2008/104 (the first question)

1. Preliminary remarks

22. By its first question, the national court seeks to establish whether Article 4(1) of Directive 2008/104 imposes on the Member States an obligation to abolish prohibitions and restrictions on the use of temporary agency work that cannot be justified on grounds of general interest.

23. The parties to the main proceedings and the interested parties are divided as to the interpretation to be given to that provision.

24. Some parties consider that the provision requires the Member States to remove any restrictions on the use of temporary agency work that cannot be justified. ( 4 )

25. Other parties ( 5 ) maintain, on the other hand, that Article 4(1) of Directive 2008/104 does not lay down any substantive obligation, and must be read together with Article 4(2). The latter provision imposes an obligation on the Member States to complete a review of applicable restrictions on temporary agency work, before the deadline for transposing Directive 2008/104, in order to ascertain whether they remain justified on the ‘grounds mentioned in paragraph 1’. The scope of paragraph 1 is thus merely to define the subject-matter of the review. In particular, it does not impose on the Member States any obligation to achieve the specific result of ensuring that existing restrictions in their legislation are indeed justified on grounds of general interest.

2. Literal and teleological interpretation

26. According to the wording of Article 4(1) of Directive 2008/104, prohibitions and restrictions on the use of temporary agency work ‘shall be justified only on grounds of general interest’. There then follows an illustrative list of such grounds.

27. That wording supports the interpretation of the provision in question according to which restrictions that are not justified on grounds of general interest, of which an illustrative ( 6 ) list is given, are incompatible with EU law. Indeed, if the provision were silent on the compatibility of restrictions with EU law, the phrase ‘shall be justified only’ on grounds of general interest would be devoid of meaning.

28. That wording clearly expresses a substantive rule entailing a prohibition on unjustified restrictions. Contrary to the position maintained by a number of the parties, ( 7 ) it seems to me hard to accept that this is a purely procedural provision, similar to those contained in the subsequent paragraphs of Article 4.

29. That interpretation seems to me to be corroborated by the teleological considerations which underlie the regulation.

30. None of the parties disputes that Directive 2008/104 relates, first, to working conditions for temporary agency workers and, secondly, to the conditions which apply to the use of temporary agency work.

31. That two-fold objective — which is reflected in the title itself of Directive 2008/104 ( 8 ) — is expressed in Article 2 of the directive, which refers, on the one hand, to the need to ensure the protection of temporary agency workers and to improve the quality of temporary agency work, in particular by ensuring that the principle of equal treatment applies to temporary agency workers, and, on the other, to the need to establish a suitable framework for temporary agency work with a view to contributing effectively to the creation of jobs and the development of flexible forms of working. ( 9 )

32. The two components of this objective are complementary, and it does not therefore seem coherent to separate them. Increasing the level of protection for temporary agency workers may indeed call into question the need for certain existing prohibitions or restrictions, and consequently increase the attractiveness of this form of work. ( 10 )

33. That characteristic is, to a certain degree, common to all three European Union measures concerning atypical work, which address part-time and temporary work relationships. ( 11 ) The overall objective of the European Union’s action in this area has been to develop flexible forms of work, while at the same time seeking to achieve a new degree of harmonisation in the field of social law. ( 12 ) The regulatory model on which this action is based, which is designed to achieve a balance between flexibility and security in the job market, has been christened ‘flexicurity’. ( 13 )

34. According to this model, the use of flexible forms of work should help to increase the ability of the employment market to adapt, create more jobs and improve access for certain vulnerable groups, such as young workers, to permanent employment. In the view of some, this type of employment can serve as a ‘stepping stone’ into the job market. ( 14 )

35. The duality of the objective of Directive 2008/104 is reflected in its structure, which, leaving aside the introductory provisions (scope, aim and definitions) and final provisions, is organised into two main elements: Chapter II, which deals exclusively with the working conditions of temporary agency workers, and Article 4, which appears in Chapter I and addresses restrictions on the use of temporary agency work.

36. I find it difficult to see how Article 4 could assist in the achievement of the objectives of Directive 2008/104 if it did no more than impose a simple obligation on the Member States to identify obstacles to temporary work, without stipulating in any way what consequences flow from those obstacles.

37. To my mind, in light of its objective, Article 4 must be interpreted as laying down not only procedural obligations (paragraphs 2 to 5) but also a substantive rule (paragraph 1). That substantive rule prohibits the continued application of restrictions on the use of temporary agency work that are not justified, in particular in view of the harmonisation of minimum conditions of employment. ( 15 )

38. Article 4(2) to (5) establish a procedural mechanism to assist in the implementation of that prohibition, by means of the review of existing national restrictions, alongside the usual means of implementing EU law. If Article 4(1) contained no prohibition on unjustified restrictions, that procedural mechanism would lose its raison d’être.

39. It seems to me unreasonable to claim that the EU legislature intended merely to provide that the Member States should draw up a non-binding inventory of restrictions of a purely informative nature and requiring no follow up. Indeed, the Commission has power to collect information of that kind as part of its general remit under the Treaties to ensure the application of EU law.

40. Academic legal writers are almost unanimous in interpreting Article 4(1) of Directive 2008/104 as imposing on the Member States an obligation to remove unjustified restrictions on the use of temporary agency work. ( 16 ) Some authors say that the provision is obviously intended to strike a fair balance between internal market freedoms and social law, and that it would be wholly ineffective if it were to be interpreted as a mere recommendation. ( 17 )

41. The same reasoning seems to have inspired the joint declaration published by the social partners at European level in the temporary work sector shortly before the formal adoption of Directive 2008/104. That declaration recognised the necessity of certain restrictions to prevent abuses while also stating that unjustified restrictions should be removed. ( 18 )

3. Preparatory work

42. The preparatory work also appears to indicate that Article 4(1) of Directive 2008/104 is binding in nature.

43. Some of the parties maintain the opposite, ( 19 ) pointing out that the proposal for a directive submitted by the Commission to the Council of the European Union contained, in Article 4(2), an express provision requiring the Member States to review any restrictions on the use of temporary agency work in order to verify whether they were justified and, ‘[i]f not, … [to] discontinue them’. ( 20 ) Since that last clause was withdrawn during the course of discussions within the Council, ( 21 ) that implies, according to the parties in question, that the Council did not wish to prohibit unjustified restrictions.

44. That reasoning seems to me to be misguided.

45. First of all, the amendment made by the Council during the legislative process concerned Article 4(2) of Directive 2008/104, which deals with the review procedure. Article 4(1), on the other hand, the provision at issue in this case, was incorporated into the Council’s common position without alteration.

46. Moreover, the list of grounds of general interest set out in Article 4(1) was much debated during the legislative process. ( 22 ) Why would the institutions have accorded such significance to that provision if it was devoid of any binding character?

47. The reasons for which the passage in question, which required the Member States to ‘discontinue’ restrictions, was removed from Article 4(2) cannot be established with certainty. However, the most plausible explanation seems to be that the Council removed the clause because the prohibition on unjustified restrictions already appeared in Article 4(1), which remained unchanged.

48. Indeed, in the statement of reasons for the common position, the Council stated that it was ‘essentially following the spirit of the Parliament’s amendment 34’, ( 23 ) but ‘did not consider it necessary to retain an explicit reference to the discontinuation of unjustified restrictions and prohibitions’. ( 24 ) It its communication to the Parliament concerning the common position, the Commission stated that Article 4(2) of Directive 2008/104 followed Parliament’s amendment 34 ‘except insofar as it no longer [referred] to Member States being subject to an obligation to discontinue any restrictions or prohibitions ... since the Council did not consider it necessary to repeat the effect of the prohibition at Article 4(1) or appropriate to stipulate the final outcome of the review exercise’. ( 25 ) The common position was then approved by Parliament on the basis of those considerations. ( 26 )

49. The antecedents to the adoption of Directive 2008/104 therefore support the interpretation according to which Article 4(1) of the directive prohibits the continued application of restrictions on the use of temporary agency work that are not justified on grounds of general interest.

4. Legal basis

50. Lastly, the German Government has expressed doubt as to whether the legal basis for Directive 2008/104 permits the insertion of a substantive provision aimed at the removal of restrictions on the use of temporary agency work.

51. I would observe that the legal basis for a measure is relevant to its interpretation in that it may throw light on the objectives pursued by the legislature. Moreover, consideration must be given to the legal basis in order to exclude from the various possible interpretations of the measure any interpretation that could lead to the invalidity of the measure.

52. Directive 2008/104 is based on the former Article 137(1) and (2) EC, which conferred competence on the institutions to ‘adopt, … by means of directives, minimum requirements for gradual implementation’ relating, inter alia, to ‘working conditions’.

53. Some of the parties ( 27 ) maintain that that legal basis excludes the possibility of interpreting Article 4(1) of Directive 2008/104 as prohibiting unjustified restrictions on the use of temporary agency work. They submit that such a restriction does not fall within the purview of ‘working conditions’ and, moreover, does not constitute a ‘minimum requirement’ within the meaning of the former Article 137 EC.

54. I am not convinced by the logic of that argument.

55. It seems to me beyond question that Directive 2008/104 pursues a two-fold objective and that it concerns not only the working conditions of temporary agency workers but also restrictions on the use of that form of work. If it were otherwise, Article 4, however it was interpreted, would be meaningless.

56. According to the argument of the abovementioned parties, the former Article 137 EC does not preclude Directive 2008/104 from addressing the use of temporary agency work. Those parties nevertheless maintain that that legal basis enables only ‘limited’ or ‘purely procedural’ obligations to be imposed on the Member States with regard to such restrictions.

57. I would point out in this connection that the choice of legal basis for a measure must rest on objective factors, in particular the aim and the content of the measure. ( 28 ) However, I see no objective factor which could justify the drawing of a distinction, under the former EC Treaty, between substantive provisions and procedural provisions concerning the removal of restrictions on the use of a certain form of work.

58. If one were to take the view that the legal basis chosen for Directive 2008/104 did not permit the inclusion of provisions concerning the use of temporary agency work, that approach would result in the invalidity of Article 4 of the directive, irrespective of whether the obligations which it imposes on the Member States are procedural or substantive.

59. The argument that the former Article 137 EC enabled only certain procedural obligations to be included therefore fails to convince me.

60. One then has to ask whether interpreting Article 4 of Directive 2008/104 as prohibiting unjustified restrictions on the use of temporary agency work does not call into question the validity of that provision.

61. I would point out that, according to settled case-law, if examination of an EU measure reveals that it pursues a two-fold purpose or that it has a two-fold component and if one of those is identifiable as the main or predominant purpose or component, whereas the other is merely incidental, the act must rest on a single legal basis, namely, that required by the main or predominant purpose or component.

62. It is only by way of exception, in the event that it is established that the measure simultaneously pursues a number of objectives that are inseparably linked without one being secondary and indirect in relation to the other, that the measure may be founded on the various corresponding legal bases. ( 29 )

63. The main component of Directive 2008/104 is comprised of the provisions relating to working conditions. Article 4 clearly occupies an ancillary position. That relationship is apparent both from the structure of Directive 2008/104 (in which an entire chapter is devoted to working conditions) and from the reasoning followed at the time of the directive’s adoption, that is to say that it is only after working conditions have been harmonised that a certain degree of liberalisation of temporary work may prove to be justified.

64. The fact that Directive 2008/104 falls within the purview of the social provisions of the Treaty does not therefore prevent it from pursuing, as an ancillary objective, the removal of certain restrictions on temporary work.

65. To illustrate the point, I would observe that Directive 97/81 on part-time work, which was adopted on the basis of the social provisions of the Treaty, also pursues a two-fold purpose, consisting in the promotion of part-time work and the elimination of discrimination between full-time workers and part-time workers. Moreover, that directive contains a provision aimed at the elimination of obstacles to part-time work. ( 30 )

66. In light of those considerations, I consider that Directive 2008/104 was adopted on the basis of the former Article 137 EC correctly, without any reference to the former Articles 47(2) EC and 55 EC, which relate to services, despite the fact that it contains, in Article 4, certain provisions which apply to restrictions on the provision of services in the field of temporary work.

5. Compatibility with Article 28 of the Charter

67. The applicant in the main proceedings, relying on the principle of the autonomy of the social partners, also disputes that the prohibition on unjustified restrictions on the use of temporary agency work applies to clauses in collective agreements. It maintains that such clauses enjoy immunity as a result of the fundamental right to collective bargaining enshrined in Article 28 of the Charter.

68. I would observe that it is settled case-law that Articles 45 TFEU, 49 TFEU and 56 TFEU apply not only to acts of official bodies, but also to bodies of rules of other kinds intended collectively to govern employment, self-employment and the provision of services. The Court has confirmed on a number of occasions that collective agreements are not excluded from the scope of provisions relating to the freedoms protected under the Treaty. ( 31 ) Accordingly, where a measure or a collective agreement contains a provision restricting the use of temporary agency workers, it falls within the scope of Article 56 TFEU.

69. While the autonomy of the social partners is fully recognised in EU law, their right to negotiate and conclude collective agreements must be exercised in accordance with the law, including EU law. ( 32 )

70. The Court has thus held that the social partners must comply with the provisions of secondary EU law which give specific expression to the principle of non-discrimination in the field of employment and occupation. The fact that secondary EU law might preclude a provision of a collective agreement does not interfere with the right to negotiate and conclude collective agreements recognised in Article 28 of the Charter. ( 33 ) If a provision in a collective agreement is precluded by EU law, the national court must disapply that specific provision. ( 34 )

71. In my opinion, those considerations apply with equal force to Article 4(1) of Directive 2008/104, since it contains a mandatory rule that gives effect to a freedom protected by the Treaty and is not coupled with any derogation in favour of collective agreements. ( 35 )

72. That approach is consistent with the fact that the provisions of EU directives in the field of employment law may be implemented not only by legislative means, but also by means of generally applicable collective agreements. Accordingly, pursuant to Article 11(1) of Directive 2008/104, the Member States are required not only to adopt the measures necessary to comply with the directive, but also to ensure that the social partners introduce the necessary provisions by way of agreement.

73. I see no valid reason to maintain that collective agreements should enjoy a privileged status by comparison with the legislation of the Member States and escape the application of EU rules.

74. Those considerations in no way imply that the freedom to provide services takes precedence over the right to collective bargaining. The fact that certain restrictions on the content of collective agreements may be laid down in mandatory rules does not interfere with the exercise of that fundamental right.

75. The right of collective bargaining enshrined in Article 28 of the Charter does not, therefore, preclude the interpretation of Article 4(1) of Directive 2008/104 according to which restrictions in collective agreements on the use of temporary agency work must be justified on grounds of general interest, failing which they must be declared incompatible with EU law.

6. The role of the national courts

76. I would draw the Court’s attention to a broader teleological interpretation.

77. The legal order of the European Union rests upon the systemic principle that recognises the essential role of the national courts in implementing its provisions.

78. Within the system established by Article 267 TFEU, the tasks attributed to the national courts and to the Court of Justice respectively are indispensable to the preservation of the very nature of EU law. A provision which would deprive courts of Member States of their powers in relation to the interpretation and application of EU law and the Court of its powers to reply to questions referred to it for a preliminary ruling would alter the essential character of the powers which the Treaties confer on the institutions of the European Union and on the Member States and which are indispensable to the preservation of the very nature of EU law. ( 36 )

79. The interpretation advocated by certain Member States in this case, according to which the Member States must review restrictions on the use of temporary agency work but are under no obligation as regards the outcome of that review, seems to me to be irreconcilable with that principle.

80. According to that interpretation, the authorities of the Member States, and possibly also the social partners, would alone be responsible for identifying restrictions on the use of temporary agency work and for the conduct of the procedure which ought, logically, to lead to the alteration or removal of any unjustified restrictions.

81. In its written observations, the German Government refers, in this connection, to an ‘administrative Überprüfung’ (administrative review), whilst at the same time acknowledging that Article 4 of Directive 2008/104 might, given the spirit and purpose of the provision, contain an unwritten obligation to remove or adapt restrictions that cannot be justified.

82. The Commission argued at the hearing ( 37 ) that the interpretation according to which Article 4 of Directive 2008/104 merely lays down procedural obligations does not deprive it of its effectiveness. According to the Commission, whenever it learned of the existence of a restriction it could start a dialogue with the authorities of the Member State concerned in order to find the best way of bringing the provision into line with that directive. It could also initiate proceedings for failure to fulfil obligations.

83. Similarly, some authors criticise Article 4(1) of Directive 2008/104 on the ground that it is dangerous to leave it to national courts to assess the justifications for restrictions and their proportionality. They argue that if the application of grounds of general interest and the criterion of proportionality were left to the national courts the outcome would be as perilous and unpredictable as ‘shifting sand’. ( 38 )

84. In my view, however, it would run counter to the fundamental principles underlying the system of EU law to confer on administrative authorities exclusive competence to verify the compatibility of national legislation with a directive of the European Union, while depriving the national courts of that power.

85. Not only would such an approach exclude national courts from the process of implementing Article 4 of Directive 2008/104, it would also call into question their jurisdiction to examine restrictions on temporary agency work in the light of Article 56 TFEU.

86. An approach of that sort seems to me irreconcilable with the purpose of the system of EU law, in that it would relieve the courts of the Member States of the principal task entrusted to them in connection with the implementation of EU law.

7. Interim conclusion

87. According to recital 22 in its preamble, Directive 2008/104 is to be implemented in compliance with the provisions of the Treaty, in particular the provisions applicable to services. It is therefore necessary to consider the connection between Article 56 TFEU and Article 4(1) of Directive 2008/104.

88. I would observe that the ratio legis of Article 4(1) of Directive 2008/104 does not coincide with that of the principle of the freedom to provide services. Article 4(1) in fact provides for the lifting of unjustified obstacles to temporary work, with the aim of promoting that flexible form of work and thus promoting job creation and access to the job market.

89. Nevertheless, since temporary work implies the existence of intermediaries (temporary employment undertakings), any restriction on this form of work also constitutes a restriction on the services provided by those undertakings. The liberalisation of this form of work therefore implies the liberalisation of temporary employment services, since they are in effect the two sides of the same coin.

90. Thus, although Article 4(1) of Directive 2008/104 addresses restrictions on the ‘use of temporary agency work’ and thus concerns, prima facie, the situation of temporary agency workers, ( 39 ) it applies equally, by extension, to restrictions on the services of temporary employment agencies.

91. I would observe that restrictions on the freedom of temporary employment undertakings to provide services are already prohibited by Article 56 TFEU. ( 40 ) To the extent that restrictions on the use of temporary agency work also create an obstacle to the provision of services by temporary employment undertakings, Article 4(1) of Directive 2008/104 gives specific expression to the prohibition under Article 56 TFEU.

92. In this connection, Article 4(1) specifies the overriding reasons of general interest which are particularly likely to justify such restrictions. Moreover, it extends the application of the principle of the freedom to provide services to internal situations, since this is now a harmonised area of EU law and since the application of Directive 2008/104 does not presuppose the presence of a cross-border element.

93. In conclusion, I propose by way of answer to the first question that Article 4(1) of Directive 2008/104 prohibits the continued application or the introduction of prohibitions or restrictions on the use of temporary agency work that are not justified on grounds of general interest relating, in particular, to the protection of temporary agency workers, the requirements of health and safety at work or the need to ensure that the labour market functions properly and abuses are prevented.

8. The consequences of a different interpretation

94. Should the Court decide not to adopt my proposal and to interpret Article 4(1) as being invalid or having no normative value, I would regard it as useful for the Court to state expressly in its judgment that Article 56 TFEU remains fully applicable to restrictions such as those at issue in the present case.

95. It seems to me particularly important that this point should be made, since some of the parties appear to maintain that the restrictions at issue are not amenable to review by the national courts, either under Article 4 of Directive 2008/104 (inasmuch as that provision lays down merely procedural obligations) or under Article 56 TFEU (since the area is harmonised). ( 41 )

96. Secondary law cannot limit the scope of the fundamental freedoms. Should the Court decide that Directive 2008/104 does not prohibit the continued application of restrictions on temporary agency work, it would still remain for the national courts to verify whether such restrictions could be justified in accordance with Article 56 TFEU.

97. I would note in this connection that the rules at issue are manifestly capable of producing cross-border effects relevant to Article 56 TFEU which, accordingly, remains potentially applicable to the dispute in the main proceedings. ( 42 )

B – The justification of restrictions under Article 4(1) of Directive 2008/104 (the second question)

1. Preliminary remarks

98. By its second question, the national court seeks to establish whether a provision such as that laid down in Paragraph 29(1) of the sectoral agreement constitutes a restriction within the meaning of Article 4(1) of Directive 2008/104 and, if so, whether it may be justified.

99. I would recall that Article 4(1) of Directive 2008/104 provides that restrictions may be justified only on grounds of general interest relating, in particular, to the protection of temporary agency workers, the requirements of health and safety at work or the need to ensure that the labour market functions properly and abuses are prevented.

100. As is evidenced by the words ‘in particular’, this list is not exhaustive. Indeed, it is clear from the wording of Article 4(1) that the provision leaves open the possibility, already acknowledged in the context of the application of the freedoms enshrined in the Treaty, of justifying, on grounds of overriding public interest, restrictions which apply without distinction to national providers of services and to those from other Member States.

101. I would point out in this connection that Article 56 TFEU requires not only the elimination of all discrimination on grounds of nationality against providers of services established in another Member State but also the abolition of any restriction, even if it applies to national providers of services and to those of other Member States alike, which is liable to prohibit, impede or render less advantageous the activities of a provider of services established in another Member State where it lawfully provides similar services. ( 43 )

102. A restriction which applies without distinction may nevertheless be justified where it meets overriding requirements relating to the public interest, provided that that interest is not already safeguarded by the rules to which the service provider is subject in the Member State in which it is established and in so far as it is appropriate for securing the attainment of the objective which it pursues and does not go beyond what is necessary in order to attain it. ( 44 )

103. Those considerations, which apply in principle to areas that have not been harmonised at EU level, are equally relevant in the present case, since Article 4(1) of Directive 2008/104 gives specific expression to Article 56 TFEU in the field of temporary agency work.

104. I would observe in this connection that Article 4(1) of Directive 2008/104 also covers restrictions which apply to the services provided by temporary employment undertakings to the extent that such restrictions restrict the use of temporary work. Article 56 TFEU thus remains applicable to national provisions which affect the services provided by temporary employment undertakings other than those which relate to the ‘use of temporary agency work’. ( 45 )

105. The coherent application of the provisions in question demands that requirements regarding the justification of the restrictions referred to in Article 4(1) of Directive 2008/104 be identical to those which apply to the application of Article 56 TFEU. That is corroborated by the close relationship between those two provisions and by recital 22 in the preamble to Directive 2008/104, which emphasises that the provisions of the directive must be applied in compliance with primary law relating to the freedom of establishment and the freedom to provide services.

2. The purpose of the restrictions

106. In so far as concerns the clause at issue in the dispute in the main proceedings, I would recall that it comprises two distinct provisions: — the first, which describes the nature of the tasks that may be entrusted to temporary workers, refers only to tasks which are ‘of limited duration or of a specific nature’ and which, ‘for reasons of urgency or because of their limited duration or skill requirements or the use of special tools or other similar reasons’, cannot be performed by the employees of the undertaking in question; and — the second, which seeks to limit the duration of employment of temporary workers in any given undertaking, characterises as an ‘unfair practice’ situations in which temporary agency workers ‘carry out the undertaking’s usual work alongside the undertaking’s permanent workers under the same management and for a long period of time’.

107. A reading of those two provisions together shows that the possibility of having recourse to temporary labour is limited by the nature of the tasks carried out and by the duration of those tasks. The provisions thus restrict the use of this form of work and also have a restrictive effect on the services provided by temporary employment undertakings. They are therefore, indisputably, restrictions within the meaning of Article 4(1) of Directive 2008/104.

3. Justification on grounds of general interest

108. The majority of the parties to the proceedings, with the exception of the defendants in the main proceedings, maintain that the restrictions at issue are justified on the ground of a general interest relating to the need to ensure that the labour market functions properly and abuses are prevented.

109. As the Finnish Government explains, the aim is to prevent tasks which fall within the scope of stable employment relationships from being entrusted, without due cause, to temporary agency workers and thus to ensure that the use of temporary agency work does not lead to the loss of employment posts within user undertakings.

110. I would observe in this connection that it is apparent from the reasons on the basis of which Directive 2008/104 was adopted that temporary agency work is not regarded as a substitute for stable forms of work.

111. First, the legislative action of the European Union in the area of employment law is based on the fundamental premiss that contracts of indefinite duration are the general form of employment relationship. ( 46 ) Moreover, the provisions of Directive 2008/104, in particular Article 6 thereof which relates to access for temporary agency workers to employment in user undertakings, also demonstrate that direct employment is the preferred working relationship, rather than temporary employment.

112. Secondly, it is clear from the definitions set out in Article 3 of Directive 2008/104 that temporary agency work implies relationships which are maintained ‘temporarily’. ( 47 ) It may be inferred from that that this form of work is not appropriate in all circumstances, in particular, where staffing needs are permanent.

113. Notwithstanding, Directive 2008/104 does not define temporary agency work, nor does it list the cases in which the use of this form of work may be justified. Recital 12 in its preamble does, however, state that the directive is intended to respect the diversity of labour markets.

114. Given that the EU legislature has chosen not to define the situations in which the use of temporary agency work is justified, the Member States retain a broad discretion in that regard.

115. That broad discretion stems from the competence of the Member States to make political choices affecting the development of the employment market and to legislate accordingly, in accordance with EU law. It is also confirmed by the existence of the clause pertaining to the prevention of social regression contained in Article 9(2) of Directive 2008/104. Indeed, the Member States must enjoy significant freedom of action in order to ensure that the removal of certain restrictions does not lead to a reduction in the general level of protection of workers in the area in question.

116. To my mind, a Member State may, without overstepping the bounds of that discretion, provide that the use of temporary agency work is permitted in circumstances which are consistent with the temporary nature of that form of work, albeit that temporary work must not have a detrimental effect on direct employment.

117. It is for the national court to determine whether Paragraph 29(1) of the sectoral agreement under consideration in the main proceedings is justified in the light of that last consideration.

118. Nevertheless, I would like to say that the wording of that clause tends to suggest that that is the case.

119. First, given the nature of temporary work, as described in points 111 and 112 above, it seems to me to be justified to restrict the use of this form of work, as is provided in Paragraph 29(1) of the sectoral agreement, to ‘dealing with peaks of work or to the performance of other tasks of limited duration or of a specific nature which, for reasons of urgency or because of their limited duration or skill requirements or the use of special tools or other similar reasons, [user undertakings] cannot have been performed by their own staff’.

120. Secondly, inasmuch as the provision at issue prohibits the employment of temporary agency workers alongside an undertaking’s own employees for a ‘long period of time’, it does, in my view, pursue the legitimate objective of limiting the abusive use of that form of work. Indeed, in accordance with the general thrust of EU legislation, the use of temporary agency work must not have a detrimental effect on direct employment but must, on the contrary, be able to lead to more secure forms of employment.

121. The continuance, for a long period of time, of temporary employment relationships, which should by nature remain temporary, might in fact be indicative of an abuse of this form of work.

122. I would observe that the adoption of measures to prevent abuses in the conclusion of temporary employment contracts cannot justify an almost general exclusion of that form of work, such as a prohibition on temporary work across an entire economic sector or the fixing of quotas for temporary contracts, in the absence of any other objective justification. Indeed, a measure that is intended to prevent abuses in the exercise of a right cannot be regarded as the equivalent of a renegotiation of the right in question.

123. That is not the situation in the present case, since the restrictions at issue go no further than describing objective reasons justifying the use of temporary labour and do not seek to eliminate that form of work.

124. Consequently, national rules such as those at issue in the dispute in the main proceedings, which limit the use of temporary work to the performance of tasks which, by reason of their nature or duration, objectively meet a temporary need for labour and which prohibit the employment of temporary agency workers alongside an undertaking’s own employees for a long period of time, seem to me to be justified on the ground of a general interest relating to the need to ensure that the labour market functions properly and abuses are prevented.

4. Proportionality

125. As regards the proportionality of these restrictions, I would observe that the observations submitted by the parties point to a great diversity in the approaches taken by the Member States to possible restrictions on temporary agency work. ( 48 )

126. The varying intensity of the restrictions on the use of temporary agency work in the Member States cannot, however, affect the appraisal as to the need for and proportionality of the provisions under examination. ( 49 )

127. Whilst it is for the national court to carry out the assessment of proportionality, I would nevertheless observe at the outset that the restrictions imposed by the clause at issue do not appear to me to go beyond what is necessary to achieve the objective pursued by the legislation.

128. First, the restrictions are closely connected with the legitimate objectives pursued, inasmuch as they are solely intended to convey in plain words the temporary nature of temporary agency work and thus to prevent that form of work from substituting for direct employment. Secondly, inasmuch as they apply to ‘other tasks’ and for a ‘long period of time’, the restrictions appear to be sufficiently general to enable the particular situation of each user undertaking to be taken into account.

5. Interim conclusion

129. In conclusion, I consider that Article 4(1) of Directive 2008/104 does not preclude national rules which, first, restrict the use of temporary agency work to the performance of tasks that are temporary and which, for objective reasons, cannot be carried out by workers employed directly by the user undertaking and, secondly, prohibit the employment of temporary agency workers alongside workers employed directly by the user undertaking to carry out tasks identical to those carried out by its own workers for a long period of time.

C – The effect of the provision being interpreted within the national legal system (the third question)

130. By its third question, the national court raises the issue of the role which EU law requires it to play in the event that it should find that the clause at issue is incompatible with Article 4(1) of Directive 2008/104.

131. There is no need to answer this question, given the answer which I propose to the second question. Nevertheless, I shall analyse it briefly.

132. It is appropriate to recall, first of all, that national courts are bound by the obligation to interpret national law in conformity with EU law, that obligation also extending to the provisions of collective agreements. ( 50 )

133. The national court asks whether national law may be interpreted in conformity with Directive 2008/104, since that directive and the sectoral agreement appear to adopt contradictory approaches as regards temporary employment and given that Finnish law contains no specific provisions transposing the prohibition contained in Article 4(1) of Directive 2008/104.

134. I would point out in this connection that the obligation to interpret national law in conformity with EU law does not entail an interpretation merely of the national provisions introduced in order to transpose Directive 2008/104, but requires national law as a whole to be considered in order to assess to what extent it may be applied so as not to produce a result contrary to that sought by the directive. ( 51 )

135. The lack of implementing measures does not, therefore, prevent the national court from ascertaining, on the basis of national law considered as a whole, whether it can, by means of interpretation, achieve an outcome consistent with EU law.

136. In order to address the possibility that a consistent interpretation cannot be achieved, it is necessary to consider whether Article 4(1) of Directive 2008/104 has direct effect.

137. In view of its content, it appears that Article 4(1) is capable of having direct effect. It is nevertheless necessary to consider whether the defendants in the main proceedings may rely on that provision against a trade union.

138. Although the Court has not, to date, recognised the horizontal direct effect of EU directives, ( 52 ) it may nevertheless be inferred from the case-law that the fundamental freedoms protected by the Treaty do have horizontal direct effect, in the sense that they may be relied on directly by an undertaking against a trade union or group of trade unions. ( 53 )

139. It would appear logical to me to accept that Article 4(1) of Directive 2008/104, which gives specific expression to the prohibition on restrictions on the freedom to provides services, in the specific area of temporary employment, has the same effect.

140. Indeed, prior to the adoption of Directive 2008/104, national measures which restricted the use of temporary agency work, and therefore also raised an obstacle to the provision of services in that area, potentially fell within the scope of the prohibition laid down in Article 56 TFEU. In my view, it would be somewhat illogical to permit such measures to escape that prohibition merely because it is now given specific expression in Directive 2008/104 and because directives do not, in principle, apply directly to relationships between individuals.

141. To be clear on the point, I do not intend to add to the debate concerning the direct horizontal effect which certain principles of EU law might have, in particular, when they are given specific expression in a directive. ( 54 )

142. The situation in the present case is, in my view, far less controversial, since Article 4(1) of Directive 2008/104 in no way alters the substantive content of Article 56 TFEU, which, according to existing case-law, does have direct effect in certain horizontal relationships.

143. Indeed, Article 4(1) merely sets out a prohibition on unjustified restrictions on temporary agency work in an instrument of secondary legislation which harmonises this area (whereas such restrictions were previously contained in Article 56 TFEU), and to set out the grounds of general interest capable of justifying those restrictions.

144. Moreover, the harmonisation achieved in this area is such that the presence of a cross-border element is no longer necessary, although it would have been necessary in order for the provisions relating to the fundamental freedoms to apply. Indeed, it is not in dispute that Directive 2008/104 applies to internal situations.

145. I would, however, observe that, leaving aside Directive 2008/104, the application of Article 56 TFEU to a dispute such as that before the national court is not impossible, notwithstanding the fact that it involves persons within the same Member State.

146. Indeed, the clause at issue is manifestly capable of producing cross-border effects relevant for the purposes of Article 56 TFEU, in particular, since it could impede Shell’s access to services provided by temporary work undertakings established in other Member States. ( 55 ) In a situation such as this it seems to me pointless to seek out a cross-border element, of an incidental nature, such as whether, during the relevant period, Shell had recourse to a temporary work agency established outside Finland, or whether any of the temporary agency workers who worked for Shell during that period came from another Member State.

147. Consequently, in the event that the Court should regard it as necessary to consider the third question, I would propose by way of answer to that question that Article 4(1) of Directive 2008/104 may be relied on by an undertaking against a trade union.

VI – Conclusion

148. In light of the foregoing considerations, I propose that the Court should answer the questions referred by the työtuomioistuin for a preliminary ruling as follows: (1) Article 4(1) of Directive 2008/104/EC of the European Parliament and of the Council of 19 November 2008 on temporary agency work must be interpreted as prohibiting the continued application or the introduction of prohibitions or restrictions on the use of temporary agency work that are not justified on grounds of general interest relating, in particular, to the protection of temporary agency workers, the requirements of health and safety at work or the need to ensure that the labour market functions properly and abuses are prevented. (2) Article 4(1) of Directive 2008/104 does not preclude national rules which, first, restrict the use of temporary agency work to the performance of tasks that are temporary and which, for objective reasons, cannot be carried out by workers employed directly by the user undertaking and, secondly, prohibit the employment of temporary agency workers alongside workers employed directly by the user undertaking to carry out, for a long period of time, tasks identical to those carried out by the user undertaking’s own workers.

( 1 ) Original language: French.

( 2 ) Directive of the European Parliament and of the Council of 19 November 2008 (OJ 2008 L 327, p. 9).

( 3 ) Agreement concluded on 4 June 1997 by the Teollisuuden ja Työnantajain Keskusliitto (which subsequently became the Elinkeinoelämän keskusliitto, the central federation for economic activity) and the Suomen Ammattiliittojen Keskusjärjestö (the central organisation for Finnish trade unions).

( 4 ) The defendants in the main proceedings and the Hungarian Government. The referring court has also expressed the same view. The French and Polish Governments have made no observations on the matter.

( 5 ) The applicant in the main proceedings and the Finnish, German, Swedish and Norwegian Governments. The Commission, which has altered its stance during the course of these proceedings, appears to propose the same interpretation.

( 6 ) In so far as concerns the non-exhaustive nature of the list, see point 100 below.

( 7 ) The Finnish, German, Swedish and Norwegian Governments and — at the hearing — the Commission.

( 8 ) The title given in the initial legislative proposal, ‘Directive ... on working conditions for temporary workers’, was amended on first reading in the European Parliament to ‘Directive … on temporary agency work’ on the ground that ‘the aims and content of the directive [were] broader than just “working conditions”, extending to cover the promotion and regulation of the temporary work agency sector’, and that this was more consistent with previous directives on part-time and fixed-term work (see the justification for amendment 1 given in the Parliament’s legislative resolution A5-0356/2002 of 23 October 2002).

( 9 ) Recitals 9 to 11 in the preamble to Directive 2008/104 emphasise the importance of new forms of work organisation to job creation, one of the principle objectives of the Lisbon Strategy.

( 10 ) See recital 18 in the preamble to Directive 2008/104.

( 11 ) These are, in addition to Directive 2008/104, Council Directive 97/81/EC of 15 December 1997 concerning the Framework Agreement on part-time work concluded by UNICE, CEEP and the ETUC (OJ 1998, L 14, p. 9) and Council Directive 1999/70/EC of 28 June 1999 concerning the framework agreement on fixed-term work concluded by ETUC, UNICE and CEEP (OJ 1999 L 175, p. 43).

( 12 ) It was this objective that inspired the Commission’s consecutive proposals in the field of atypical work: Proposal for Council Directive supplementing the measure to encourage improvement in the safety and health at work of temporary workers COM(90) 228 of 29 June 1990, which was largely unsuccessful, and Proposal SEC(1995) 1540, under which a consultation with the social partners was launched which led to the adoption of the two framework agreements on part-time work and fixed-term work.

( 13 ) See Common Principles of Flexicurity, adopted by the Council on 5 and 6 December 2007 and approved by the Brussels European Council of 14 December 2007 (Council doc. 16201/07). See also the Commission communication to the European Parliament, the Council, the European Economic and Social Committee and the Committee of the Regions, entitled ‘Towards Common Principles of Flexicurity: More and better jobs through flexibility and security’ (COM(2007) 359 final of 27 June 2007).

( 14 ) See Bell, M., ‘Between flexicurity and fundamental social rights: the EU directives on atypical work’, European law review, 2012, Vol. 37, no 1, p. 36; Davies, A., ‘Regulating atypical work: beyond equality’, Resocialising Europe in a time of crisis, 2013, p. 237.

( 15 ) In accordance with the clause pertaining to the prevention of social regression contained in Article 9(2) of Directive 2008/104, this harmonisation must not lead to a reduction in the general level of protection of workers in the field in question.

( 16 ) See, in particular, Bell, M., op. cit., p. 36; Davies, A., op. cit., p. 237; Countouris, N., and Horton. R., ‘The Temporary Agency Work Directive: Another Broken Promise’, Industrial Law Journal, 2009, Vol. 38, no 3, p. 335; Lhernould, J.-P., ‘Le détachement des travailleurs intérimaires dans l’Union européenne’, Revue de droit de travail, 2012, p. 308; Weiss, M., ‘Regulating Temporary Work in Germany’, Temporary agency work in the European Union and the United States, pp. 120 to 122; Rönnmar, M., ‘The regulation of temporary agency work in Sweden and the impact of the (2008/104/EC) Directive’, European Labour Law Journal (ELLJ), 2010, Vol. 1, no 3, pp. 422 to 429.

( 17 ) Respectively, Engels, C., ‘Regulating temporary work in the European Union: The Agency Directive’, Temporary agency work in the European Union and the United States, 2013, no 82, p. 14; Mitrus, L., ‘Ochrona pracowników tymczasowych w świetle prawa unijnego a prawo polskie’, Sobczyk A. (ed.), Z problematyki zatrudnienia tymczasowego, Wolters Kluwer Polska, 2011, p. 18.

( 18 ) Joint Declaration of EuroCIETT (European Confederation of Private Employment Agencies and UNI-Europa (a European federation of trade unions) of 28 May 2008 on the directive on working conditions for temporary agency workers, points 7 and 14 (http://www.eurociett.eu/).

( 19 ) The applicant in the main proceedings and the Finnish Government.

( 20 ) See the amended proposal for a directive of the European Parliament and the Council on working conditions for temporary workers (COM(2002) 701 final of 28 November 2002), which replaced the initial proposal of the European Parliament and the Council on working conditions for temporary workers (COM(2002) 149 final of 20 March 2002) following the first reading in Parliament.

( 21 ) Council Common Position No 24/2008 of 15 September 2008 (ST 10599 2008).

( 22 ) In particular, the Parliament amended the Commission’s initial proposal by inserting three new grounds on which restrictions could be justified (the health and safety [of] and other risks posed to certain groups of workers or sectors of economic activity, the proper functioning of the labour market and the need to prevent potential abuses). See the Parliament’s legislative resolution of 21 November 2002 (P5_TA(2002)0562) and the justification for the amendment (A5-0356/2002 of 23 October 2002).

( 23 ) Amendment 34 split Article 4(1) into two parts: ‘the first puts beyond doubt that restrictions and prohibitions on the use of temporary agency work can be maintained and/or introduced in certain circumstances ...; the second strengthens the provision for Member States’ reviews of such restrictions’. See the justification for amendment 34 given in the Parliament’s legislative resolution (A5-0356/2002 of 23 October 2002).

( 24 ) Common position No 24/2008, paragraph 2.2 of the statement of reasons.

( 25 ) Communication from the Commission to the European Parliament, pursuant to the second subparagraph of Article 251(2) of the EC Treaty concerning the Common Position of the Council on the adoption of a European Parliament and Council Directive on temporary agency work — Political agreement on a common position (QMV) (COM(2008) 569 final of 18 September 2008, p. 6).

( 26 ) European Parliament legislative resolution of 22 October 2008 (P6_TA(2008)0507).

( 27 ) The applicant in the main proceedings, the Finnish, German and Swedish Governments, and — at the hearing — the Commission.

( 28 ) See, in particular, Commission v Parliament and Council (C‑411/06, EU:C:2009:518, paragraph 45 and the case-law cited).

( 29 ) See, inter alia, Huber (C‑336/00, EU:C:2002:509, paragraph 31).

( 30 ) See clause 5(1) of Directive 97/81, and the judgment in Michaeler and Others (C‑55/07 and C‑56/07, EU:C:2008:248) and Bruno and Others (C‑395/08 and C‑396/08, EU:C:2010:329, paragraph 78). Directive 97/81 was adopted on the basis of Article 4(2) of the Agreement on Social Policy annexed to the EC Treaty, which was later incorporated into the social chapter of the EC Treaty (Article 139(2) EC).

( 31 ) Laval un Partneri (C‑341/05, EU:C:2007:809, paragraph 98) and The International Transport Workers’ Federation et The Finnish Seamen’s Union (C‑438/05, EU:C:2007:772, paragraphs 33 and 54 and the case-law cited).

( 32 ) Prigge and Others (C‑447/09, EU:C:2011:573, paragraph 47) and Erny (C‑172/11, EU:C:2012:399, paragraph 50). The same point is made in recital 19 in the preamble to Directive 2008/104.

( 33 ) Hennigs and Mai (C‑297/10, EU:C:2011:560, paragraphs 68 and 78).

( 34 ) See the Opinion of Advocate General Sharpston in Österreichischer Gewerkschaftsbund (C‑476/12, EU:C:2014:89, C‑476/12, paragraph 51).

( 35 ) A derogation of this kind is, on the other hand, provided for in Article 5(3) of Directive 2008/104 with regard to the principle of the equal treatment of temporary agency workers.

( 36 ) Opinion of the Court 1/09 (EU:C:2011:123, paragraphs 85 and 89).

( 37 ) In its written observations the Commission proposed a different interpretation, maintaining that Article 4 prohibits the continued application of unjustified restrictions on the use of temporary agency work.

( 38 ) Robin-Olivier, S., A French reading of Directive 2008/104 on temporary agency work, European Labour Law Journal, 2010, Vol. 1, no 3, p. 404.

( 39 ) For example, a prohibition on concluding a contract of indefinite duration with a temporary agency worker, a prohibition on the direct recruitment of temporary workers by the user undertaking or a prohibition on employing disabled persons as agency workers (see the Commission’s Report of the Expert Group on the Transposition of Directive 2008/104 of August 2011, pp. 29 and 31, and the report of the European Parliament, the Council, the European Economic and Social Committee and the Committee of the Regions of 21 March 2014 on the application of Directive 2008/104/EC on temporary agency work (COM(2014) 176 final, pp. 12 and 13).

( 40 ) See, for example, Commission v Belgium (C‑397/10, EU:C:2011:444) and Strojírny Prostějov and ACO Industries Tábor (C‑53/13 and C‑80/13, EU:C:2014:2011).

( 41 ) See points 80 to 83 above.

( 42 ) See points 145 and 146 below.

( 43 ) Portugaia Construções (C‑164/99, EU:C:2002:40, paragraph 16 and the case-law cited).

( 44 ) Säger (C‑76/90, EU:C:1991:331, paragraph 15) and Strojírny Prostějov and ACO Industries Tábor (EU:C:2014:2011, paragraph 44). Among the reasons of overriding public interest that have already been recognised by the Court is the protection of workers (see Portugaia Construções, EU:C:2002:40, paragraph 20).

( 45 ) See Strojírny Prostějov and ACO Industries Tábor (EU:C:2014:2011). Similarly, national requirements with regard to registration, licensing, certification, financial guarantees or monitoring of temporary-work agencies are excluded from the scope of Directive 2008/104 under Article 4(4) thereof, and thus remain potentially subject to the provisions of Articles 49 TFEU and 56 TFEU.

( 46 ) See recital 15 in the preamble to Directive 2008/104 and paragraph 7 of the general considerations to the framework agreement put into effect by Council Directive 1999/70. See also the Opinion of Advocate General Jääskinen in Jansen (C‑313/10, EU:C:2011:593, point 57).

( 47 ) See the definitions of ‘temporary-work agency’, ‘temporary agency worker’ and ‘user undertaking’ in Article 3(1)(b) to (d) of Directive 2008/104.

( 48 ) This view if borne out by report COM(2014) 176 final, pp. 9 and 10.

( 49 ) Mac Quen and Others (C‑108/96, EU:C:2001:67, paragraphs 33 and 34).

( 50 ) See, to that effect, Pfeiffer and Others (C‑397/01 to C‑403/01, EU:C:2004:584, paragraphs 101 and 119) and the Opinion of Advocate General Ruiz-Jarabo Colomer in that case (C‑397/01 to C‑403/01, EU:C:2003:245, point 59).

( 51 ) Marleasing (C‑106/89, EU:C:1990:395, paragraph 8), Pfeiffer and Others (EU:C:2004:584, paragraph 115) and Association de médiation sociale (C‑176/12, EU:C:2014:2, paragraph 38).

( 52 ) Dominguez (C‑282/10, EU:C:2012:33, paragraph 42) and Association de médiation sociale (EU:C:2014:2, paragraph 36).

( 53 ) See, to that effect, Laval un Partneri (EU:C:2007:809, paragraph 98) and the Opinion of Advocate General Mengozzi in that case (C‑341/05, EU:C:2007:291, points 159 to 161) and, with respect to freedom of establishment, International Transport Workers’ Federation and Finnish Seamen’s Union (EU:C:2007:772, paragraph 66).

( 54 ) See the recent Opinion of Advocate General Cruz Villalón in Association de médiation sociale (C‑176/12, EU:C:2013:491, points 73 to 80).

( 55 ) See, in this connection, Venturini and Others (C‑159/12 to C‑161/12, EU:C:2013:791, paragraph 26) and the Opinion of Advocate General Wahl in that case (C‑159/12 to C‑161/12, EU:C:2013:529, point 35).