OPINION OF ADVOCATE GENERAL

BOBEK

delivered on 17 May 2017 ( 1 )

Case C‑217/16

European Commission

v

Dimos Zagoriou

(Request for a preliminary ruling from the Monomeles Efeteio Athinon (Court of Appeal of Athens (single judge), Greece))

(Enforcement of Commission decision imposing a pecuniary obligation under Article 256 EC — Determination of competent court — Capacity to be made a defendant in enforcement proceedings — Principles of equivalence and effectiveness)

I. Introduction

1. In 2006 the Commission adopted a decision, ( 2 ) addressed to an undertaking owned by the commune of Aristi Zagoriou in Greece, seeking to recover aid granted to that undertaking in 1993. After the grant of the aid but prior to the adoption of the Commission Decision, the undertaking was dissolved. Moreover, the commune of Aristi Zagoriou was integrated into a larger municipal entity, Kentriko Zagori.

2. The Commission sought to enforce its decision against Kentriko Zagori, which opposed the enforcement before the national civil courts. During those court proceedings, Kentriko Zagori was in turn integrated into another larger municipal entity, Dimos Zagoriou, which is the respondent in the main case. The opposition was upheld by judgment at first instance in 2013. The national court decided that enforcement could not be made against Dimos Zagoriou.

3. The Commission appealed that decision before the referring court, a civil court of appeal, claiming that the national administrative courts and not the national civil courts were competent to hear the case. Further, it also maintained that enforcement could be sought against Dimos Zagoriou as successor of the undertaking.

4. Against this rather complex procedural background, the referring court now asks the Court whether the underlying dispute is private or public in nature, how the competent court is to be determined, and against which entities enforcement can be sought.

II. Legal framework

A. EU law

1. Treaty on the Functioning of the EU

5. Article 299 TFEU reads as follows: ‘Acts of the Council, the Commission or the European Central Bank which impose a pecuniary obligation on persons other than States, shall be enforceable. Enforcement shall be governed by the rules of civil procedure in force in the State in the territory of which it is carried out. The order for its enforcement shall be appended to the decision, without other formality than verification of the authenticity of the decision, by the national authority which the government of each Member State shall designate for this purpose and shall make known to the Commission and to the Court of Justice of the European Union. When these formalities have been completed on application by the party concerned, the latter may proceed to enforcement in accordance with the national law, by bringing the matter directly before the competent authority. Enforcement may be suspended only by a decision of the Court. However, the courts of the country concerned shall have jurisdiction over complaints that enforcement is being carried out in an irregular manner.’

2. Regulations No 2052/88, ( 3 ) No 4253/88 ( 4 ) and No 4256/88 ( 5 )

6. Regulation (EEC) No 2052/88 is the basic act regulating the EU structural funds, their interrelationship and their relationship with other financial instruments (‘Structural Funds Regulation’).

7. Regulation (EEC) No 4253/88 is the main regulation implementing the Structural Funds Regulation (‘Structural Funds Implementing Regulation’).

8. Regulation (EEC) No 4256/88 complements the Structural Funds Implementing Regulation in relation to the European Agricultural Guidance and Guarantee Fund (‘Structural Funds Implementing Regulation (EAGGF)’). Thus, Article 1(1) of the Structural Funds Implementing Regulation (EAGGF) provides that the Guidance Section of the EAGGF can be used to fund measures for performing tasks under the Structural Funds Regulation. Article 1(2) generally applies to such cases the rules set out in the Structural Funds Implementing Regulation.

9. Title VI of the Structural Funds Implementing Regulation, ‘Financial Provisions’, includes in particular Article 24 that provides as follows: ‘Reduction, suspension and cancellation of assistance 1. If an operation or measure appears to justify only part of the assistance allocated, the Commission shall conduct a suitable examination of the case in the framework of the partnership, in particular requesting that the Member State or other authorities designated by it to implement the operation to submit their comments within a specified period of time. 2. Following this examination, the Commission may reduce or suspend assistance in respect of the operation or measure concerned if the examination reveals an irregularity and in particular a significant change affecting the nature or conditions of the operation or measure for which the Commission's approval has not been sought. 3. Any sum received unduly and to be recovered shall be repaid to the Commission. Interest on account of late payment may be charged on sums not repaid in compliance with the provisions of the Financial Regulation and in accordance with the arrangements to be drawn up by the Commission pursuant to the procedures referred to in Title VIII hereof.’

III. Facts, procedure and questions referred

10. In 1993, the Dimotiki Epicheirisi Touristikis Anaptyxis Aristis Zagoriou Ioanninon, an undertaking wholly owned by the commune of Aristi Zagoriou and responsible for development of the Aristi region (‘the undertaking’) applied for and was granted aid from the European Agricultural Guidance and Guarantee Fund (‘EAGGF’). The project was terminated prematurely, and so the Commission sought recovery of part of the aid.

11. To that end, in 2006, the Commission adopted a decision addressed to the undertaking seeking repayment (‘Commission Decision’). ( 6 ) Enforcement of that decision was sought under Article 256 TEC (now Article 299 TFEU), which provides for the enforceability of acts imposing pecuniary obligations on persons other than States. Attached to the decision was an enforcement order.

12. However, prior to the adoption of the Commission Decision, the commune of Aristi Zagoriou was integrated into the municipality of Kentriko Zagori. ( 7 ) Moreover, the undertaking was dissolved. ( 8 )

13. According to the referring court’s request, on 31 August 2008 an injunction to pay the debt plus interest was addressed to Kentriko Zagori, the legal successor of Aristi Zagoriou and the sole shareholder of the undertaking (‘the injunction’). On 15 October 2008, the Commission obtained an attachment order for the amount in respect of bank assets of Kentriko Zagori.

14. The money was transferred to the Commission.

15. On 23 October 2008, Kentriko Zagori opposed the injunction before the Monomeles Protodikeio Athinon (Court of First Instance (single judge), Greece) (a civil court).

16. During the proceedings before that court, Kentriko Zagori was integrated into the municipality of Dimos Zagoriou. ( 9 )

17. By judgment of 14 May 2013, the civil court at first instance upheld the opposition on the basis that the enforcement of the debt owed by the undertaking could not be made against Dimos Zagoriou.

18. The Commission appealed before the referring court, the Monomeles Efeteio Athinon (Court of Appeal of Athens (single judge), Greece).

19. In its appeal, the Commission argues essentially that the court that heard the dispute at first instance (a civil court) did not have jurisdiction to hear the case because the dispute is administrative in nature and should be heard by the administrative courts. The Commission also argued that enforcement could be sought against Dimos Zagoriou.

20. In the light of the foregoing, the Monomeles Efeteio Athinon (Court of Appeal of Athens (single judge)) decided to stay proceedings and to refer the following questions to the Court: ‘(1) What is the nature of the acts of the European Commission when it exercises its powers pursuant to Regulations No 2052/88, No 4253/88 and No 4256/88 and, more specifically, are those acts of the Commission acts of public law and do they give rise to administrative disputes as to the substance in any event, in particular where the subject matter of the attachment by the European Commission of assets held by a third party is a private debt, whereas the initial debt for whose satisfaction enforcement is proceeded with derives from a legal relationship governed by public law which has arisen from the foregoing acts of the European Commission, or are they acts of private law and do they give rise to private disputes? (2) Having regard to the fact that, under Article 299 TFEU, enforcement of acts of the European Commission which impose a pecuniary obligation on persons other than Member States is to be governed by the rules of civil procedure in force in the State in the territory of which enforcement is proceeded with and that, under that article, the courts of the country concerned are to have jurisdiction over complaints that enforcement is being carried out in an irregular manner, how is the jurisdiction of the national courts over disputes which arise from such enforcement determined, when under national law those disputes are administrative disputes as to the substance, that is to say, when the underlying relationship is one of public law? (3) In the case of enforcement of acts of the European Commission which are adopted pursuant to Regulations No 2052/88, No 4253/88 and No 4256/88 and impose a pecuniary obligation on a person other than Member States, is the capacity to be made a defendant that is possessed by the person liable assessed on the basis of national law or of Community law? (4) When the person liable to discharge a pecuniary obligation stemming from an act of the European Commission adopted pursuant to Regulations No 2052/88, No 4253/88 and No 4258/88 is a community undertaking, which subsequently was wound up, does the community which owns that undertaking owe an obligation to discharge that pecuniary obligation to the European Commission under the foregoing regulations?’

21. Written observations have been submitted by Dimos Zagoriou, the Greek Government and the Commission. Those parties also presented oral argument at the hearing on 8 March 2017.

IV. Assessment

A. Admissibility

22. Although there might be doubts about the admissibility of the questions submitted by the national court, they certainly cannot be deemed to be unrelated to the main dispute. They thus benefit from a presumption of relevance. ( 10 ) Moreover, although in places the questions might be read as requesting this Court to interpret national law, which is clearly not its task, ( 11 ) they do also raise more general questions about the interplay between EU law and national law. Finally, any lack of clarity in the national court’s request, or absence of detail on relevant national provisions has not prevented the main parties to the dispute and the Greek Government from submitting observations.

23. For those reasons, the questions are in my view admissible. Nonetheless, as will be seen further below, I do consider that the limited detail provided by the referring court in the request for a preliminary ruling places significant limits on the level of detail into which this Court can in practice go in its response.

B. Substance

1. Questions 1 and 2

24. The main case involves opposition to the enforcement of a debt owed to the EU, established by a Commission decision imposing a pecuniary obligation. A key disagreement between the parties to the proceedings before the national court is whether it should be the administrative or civil courts that are competent to handle those types of proceedings.

25. Dimos Zagoriou and the Greek Government argue it should be the civil courts. The Commission pleads the principle of equivalence, stating that claims relating to enforcement of a debt should be heard by the same courts whether the debt is owed to the Greek State or to the Commission. I understand that for the Commission that means the administrative courts ought to be competent in both cases. That is the backdrop to the referring court’s first two questions.

26. The referring court’s second question asks in substance how to determine which national court is competent in cases such as the one before it. The referring court is concerned specifically about the effect on that choice of the nature of the legal relationships that are at the origin of the dispute (public or private). I understand it is for that reason that the referring court asks in its first question whether the legal relationships at the origin of the dispute before it are of a public or private nature.

27. Thus, it would seem to me that both the first and the second questions of the national court aim at understanding which courts are competent to hear actions relating to the enforcement of debt owed to the EU. I will therefore address those questions together.

28. It ought to be repeated that it is certainly not the role of this Court to interpret national laws relating to the competence of courts and, on that basis, to decide within which system of courts a case before the national judge is supposed to be heard. However, abstracting from the layer of national rules, the first and the second questions of the national court also pose a more general question: what requirements does EU law set out in relation to national enforcement of debts owed to the EU?

29. Central to the referring court’s questions is the interpretation of Article 299 TFEU providing that acts of the Commission imposing pecuniary obligations on persons other than States are enforceable. ( 12 ) That provision is both novel and minimalist. Novel, ( 13 ) since it makes what are essentially decisions of an international body directly enforceable at national level, without the need for any procedure for recognition by the Member State. ( 14 ) Minimalist, since it defers to national law for all matters related to enforcement.

30. In that minimalist spirit, nothing in Article 299 TFEU requires national law to choose specific courts to hear relevant disputes (administrative, civil or otherwise).

31. True, the second paragraph of Article 299 TFEU does provide that enforcement of decisions imposing pecuniary obligations shall be governed by national ‘rules of civil procedure’.

32. However, as pointed out by the Commission in its written pleadings, that provision relates only to the procedure for attaching the order for enforcement. That is in my view indeed confirmed by the structure of Article 299 TFEU. Article 299 TFEU refers to rules of civil procedure only in the first sentence of its second paragraph. The rest of the same paragraph then refers to the step of the procedure involving attachment of the enforcement order. The other paragraphs of the provision (Article 299, third and fourth paragraphs) cover subsequent steps of enforcement. They do not contain any such limitation. Thus, once the order has been attached, enforcement is carried out ‘in accordance with the national law’ (Article 299, third paragraph, TFEU) and is subject to judicial control by ‘the courts of the country concerned’ (Article 299, fourth paragraph, TFEU).

33. It therefore appears that the reference to ‘the rules of the civil procedure’ was meant to be limited to the procedure for attaching the order for enforcement. For the rest and all the other steps, the wording of Article 299 TFEU is entirely neutral as to the national institutions that are supposed to enforce the acts of EU institutions imposing pecuniary obligations on person other than States.

34. Moreover, I do not see (nor indeed have any of the parties invoked) any provision in the Structural Funds Regulation, Structural Funds Implementing Regulation, or Structural Funds Implementing Regulation (EAFGG) that requires designation of specific types of courts.

35. In the absence of any specification in EU law as to the competent national courts, and in accordance with established case-law, designation of those courts falls within the scope of national procedural autonomy, subject to the principles of equivalence and effectiveness. ( 15 )

36. That is the short answer to the referring court’s questions about how the competent court is to be designated. However, in order to best assist the referring court, I consider it useful at this stage to look in more detail at how the principles of equivalence and effectiveness might come into play in the present case. In doing so, I shall consider the referring court’s specific concerns about the choice between administrative and civil courts and the impact of the public/private law nature of the legal relationships between the parties which are at the origin of the dispute.

37. I agree with the Commission that nothing in the request would indicate the existence of an issue under the principle of effectiveness in relation to the designation of the competent court. ( 16 ) There is, in particular, no hint that there may be a problem of access to national courts. It is rather the type of courts — civil or administrative — that is at issue.

38. However, application of the principle of equivalence to the present case is arguably less obvious. That is, indeed, the Commission’s main point in relation to the second question. The Commission basically argues that the purpose of the proceedings is the recovery of wrongly paid aid and enforcement of that recovery. According to the Commission, whether such proceedings relate to aid paid from national resources by the Greek State, or aid paid from EU resources by the Commission, the principle of equivalence requires that the same courts should be competent. Either it should be administrative courts in both cases, or civil courts in both cases.

39. In my opinion, the answer is more nuanced. It requires a more detailed consideration of what the principle of equivalence implies in a case like the present one.

40. In general, the principle of equivalence requires a double comparison. ( 17 ) First, it is the identification of comparable ‘proceedings’ or ‘actions’ and, second, an assessment of whether EU law-based actions are treated less favourably than comparable national law-based actions.

41. Comparability of proceedings is determined by considering ‘both the purpose and the essential characteristics of allegedly similar domestic actions’. ( 18 ) In some cases, the Court refers to ‘purpose, cause of action and essential characteristics’. ( 19 ) Where actions are determined to be similar, they must be treated similarly. In order to determine whether there is similar treatment and the principle of equivalence is respected, the national court must ‘verify objectively, in the abstract, whether the rules at issue are similar taking into account the role played by those rules in the procedure as a whole, as well as the operation of that procedure and any special features of those rules’. ( 20 )

42. The case-law tends to be arguably somewhat ambiguous as to what ‘equivalent’ or ‘similar’ treatment entails. In some cases the Court has taken a ‘strict’ approach, apparently requiring identical treatment (application ‘without distinction’ to EU and national law-based claims ( 21 )). In others (which is indeed the more common variation) the Court uses more ‘flexible’ language, talking of ‘no less favourable’ treatment for EU law-based actions. ( 22 ) The latter variation clearly implies that there is scope for differences, provided those differences do not produce negative effects on EU law-based claims as compared with national law-based claims.

43. In my opinion, equivalence simply requires similarity and ‘no less favourable treatment’. It cannot mean strict identity of rules. Not only is such an arguably more reasonable and accommodating approach more broadly reflected in the case-law; it also recognises the ‘autonomy’ part of ‘national procedural autonomy’ and caters for the fact that some rules do not easily lend themselves to objective comparison.

44. Having clarified the scope of the principle, I make the following observations in relation to the present case.

(a) Similarity of proceedings

45. The first stage in applying the principle of equivalence in this case will be determining what types of proceedings to compare. In doing so, regard must be had to the ‘purpose, cause of action and essential characteristics’ ( 23 ) of the action.

46. The original action giving rise to the present reference was an action opposing enforcement by the Commission — by way of an injunction and attachment order — of a pecuniary obligation.

47. The action does not, therefore, seek to establish or contest the existence of a debt or question how it arose but rather relates to its enforcement. I am aware that, in the context of such actions relating to enforcement, some Member States in certain cases might foresee the possibility of questioning the very existence of the debt. However, it is not clear from the file whether that is so in Greece as a general matter or specifically in this case. In any event, I note that in this case: (a) the existence of the debt is not actually questioned by Dimos Zagoriou; and (b) even had it been, the referring court would not itself be competent to question the existence of the debt, since that is established by an EU act (the Commission Decision), the validity of which can only be reviewed by this Court. ( 24 )

48. My point here is this: in identifying the ‘purpose, cause of action and essential characteristics’ of an action relating to enforcement, it is not immediately obvious that the nature of the underlying relationship giving rise to the debt is actually relevant and, if so, how.

49. From a different point of view, the Commission Decision could be seen as any other executable title under national law, with its origins (public or private) being of little importance. It all depends on the national procedural rules relating to enforcement: indeed there might be national legal orders in which the enforcement of any ‘public law title’ will fall exclusively before administrative courts. However, there may also be legal systems in which enforcement before administrative courts will only be carried out with regard to decisions taken by the administrative courts themselves. Decisions coming from outside of that system would thereby necessitate an order for enforcement being appended to them. By definition, such a situation could not be compared with a final national administrative decision that will never need such treatment. Yet in other systems, all enforcement of final decisions imposing pecuniary obligations, whether coming from administrative or civil or even criminal judiciary, ( 25 ) might be channelled before civil courts, or even other officers of the law not (directly) forming part of the system of courts.

50. All these potential models have been outlined for just one purpose: to underline that it is not a given that the nature of the underlying relationship has to be a central or determining factor in the assessment of similarity of actions and application of the principle of equivalence. Depending on the parameters of the national system, once the order for enforcement has been attached to the decision, and has become enforceable under national law, the origin of the pecuniary obligation may be of little relevance.

51. It is ultimately for the national court to make the assessment of equivalence precisely because it ‘alone has direct knowledge of the procedural rules’ ( 26 ) allowing it to take a clear view on that type of question.

52. Nonetheless, with all these caveats in mind, by its first question the referring court asks about the nature of the underlying relationship between the parties in this case, implying that it considers that relationship to be of relevance in determining whether there is equivalence in the case before it. In that regard, the referring court asks whether that relationship and the debt should be classed as ‘public’ or ‘private’.

53. EU law does not make a formal distinction between ‘public’ and ‘private’ law. ( 27 ) However, to the extent it might prove of use to the referring court in its assessment of similarity of proceedings, I note that the underlying act — the Commission Decision — ‘imposes’ a pecuniary obligation (to use the same term as Article 299 TFEU). Now, wherever the precise borderline between ‘public’ and ‘private’ may lie in the individual national legal system, ( 28 ) and whatever type of the more common definition of ‘public’ that one might contemplate (power-based, interest-based, or an organic, namely, structure-based theory), the ‘imposition’ of a pecuniary obligation by a unilateral decision taken by an institution seeking the recovery of aid paid from the public purse would certainly qualify as ‘public’ under any of those approaches.

54. I stress that I do not wish to suggest that there is any formal legal distinction between public and private law under EU law or in how far such a distinction corresponds with national law(s). Instead, I mean merely to state the obvious and hardly contestable fact that by unilaterally imposing a pecuniary obligation to pay back financial aid, the Commission has clearly exercised a ‘special’ power distinct from the normal rules applicable in relations between private individuals. ( 29 ) What role that fact plays in the assessment of equivalence is a question for the referring court, subject to the further caveats outlined above in this section.

(b) Similarity of rules

55. Once the referring court has determined, on the basis of purpose, cause of action and essential characteristics, which kind of proceedings those in the main case should be compared to, it must determine whether the applicable procedural rules are similar. In that regard, the referring court is specifically concerned about choice of competent court, administrative or civil.

56. If I assume for the moment that the referring court considers that proceedings ‘similar’ to the one in the main case would normally be heard by the civil courts in any event, then there would appear to be no difference in treatment in terms of competent jurisdiction. The main case is already being heard by a civil court, as would ‘similar’ proceedings.

57. If I assume, on the other hand, that the referring court considers that proceedings ‘similar’ to the one in the main case would normally be heard by the administrative courts, then there would indeed seem to be a difference in treatment: ‘similar’ proceedings are heard by civil courts when the Commission is a party to proceedings and by administrative courts in (certain) other cases.

58. Does that application of different procedural rules in similar proceedings automatically lead to a breach of the principle of equivalence?

59. To answer that question, the national court should consider whether the rules applied ‘are similar taking into account the role played by those rules in the procedure as a whole, as well as the operation of that procedure and any special features of those rules’. ( 30 ) There will be no breach of the principle of equivalence unless application of dissimilar rules results in less favourable treatment of EU law-based claims.

60. In order to be able to carry out that assessment, however, there must be clarity and concreteness about the precise rule under examination. Similarity of rules can, by definition, only be assessed with regard to a specific rule and its operation (such as standing, prescription, time limits, fees, representation, and so on). Conversely, to assess similarity in the sense of absence of less favourable treatment with regard to an entire system of jurisdiction might be a task worthy of Judge Hercules, but hardly conceivable for anybody else.

61. Therefore, absent any concrete and specific evidence, a rule that designates administrative courts as competent, as opposed to civil courts, is not in itself obviously favourable or unfavourable to any party. I would add that nothing in the request for a reference or in the parties’ pleadings in this case indicates precisely why granting jurisdiction to civil instead of administrative courts in Greece could be unfavourable.

62. The Court’s judgment in Baczó and Vizsnyiczai clearly supports that conclusion. In that case, the Court was asked whether designating county courts as competent in certain disputes based on EU law where local courts would be competent in similar disputes based on national law breached the principle of equivalence. The Court held that it did not since the ‘[designation of] county courts to hear actions which are brought on grounds based on EU law does not necessarily constitute a procedural rule which may be classified as “unfavourable”’. ( 31 )

63. As a result, in my opinion, the designation of civil courts and administrative courts to handle similar proceedings based on EU law and national law respectively does not in itself constitute a breach of the principle of equivalence. It will only do so where that clearly constitutes, in one or more of its concrete elements of procedure, less favourable treatment for EU law-based claims. Ultimately, whether the choice of civil instead of administrative courts might be considered ‘unfavourable’ in this sense is a question for the referring court to decide.

64. As regards the idea that the rules applied including the remedies offered by civil courts might allegedly be unfavourable to the Commission, when compared to those applied by administrative courts, I would simply note that no such claim has actually been made by the Commission and the Court has otherwise received no information on that issue.

(c) Conclusion

65. In the light of the foregoing, I propose to answer the referring court’s first and second questions as such: that it is for national law, subject to the principles of equivalence and effectiveness, to determine which courts have jurisdiction to hear actions opposing the enforcement of acts of the European Commission which impose a pecuniary obligation on persons other than Member States, pursuant to Article 299 TFEU. In determining whether there is any breach of the principle of equivalence, the national court must, first, ascertain whether the proceedings concerned are similar as to their purpose, cause of action and essential characteristics, and second, examine whether the procedural rules for the actions based on EU law are less favourable than those for the actions based exclusively on national law.

2. Questions 3 and 4

66. By its third question, the referring court asks whether, when the Commission seeks to recover aid wrongly paid under the Structural Funds Regulation and its implementing regulations, the circle of persons against whom enforcement can be sought ( 32 ) is determined by national or EU law.

67. By its fourth question, the referring court asks whether, where an undertaking must repay funds it received under the Structural Funds Regulation and its implementing regulations, and has subsequently been wound up, the public authority which owns the undertaking must make the repayment.

68. Given the close relationship between the third and fourth questions, I will treat them together.

69. The Commission argues that it is the EU act referred to in the first paragraph of Article 299 TFEU (and therefore EU law) which designates the person(s) on whom the pecuniary obligation is imposed.

70. I agree. That clearly follows from the wording of the first paragraph of Article 299 TFEU itself. In the present case, that act — the Commission Decision –was addressed to the undertaking only.

71. In this case, however, the situation is made more complicated by the fact that the undertaking has since been wound up. As a result, the injunction was issued against someone else —Kentriko Zagori— and it was the bank assets of Kentriko Zagori that were subject to an attachment order.

72. It is recalled that opposition was made by Kentriko Zagori. However, before that action was judged at first instance, Kentriko Zagori was integrated into Dimos Zagoriou.

73. If enforcement is sought against a person other than the one to whom the Commission Decision was addressed, is the legal basis for that substitution of parties to be found in national law or EU law?

74. I consider that the answer is very clearly national law. Article 299 TFEU explicitly states that enforcement as a general matter is governed by national law. Moreover, I see no legal basis in the Structural Funds Regulation or their implementing regulations to enforce against person B an obligation, which was imposed on person A pursuant to those regulations and Article 299 TFEU.

75. In response to specific questions on that point during the oral hearing, the Commission was indeed unable to identify any such legal basis in EU secondary law. ( 33 )

76. To be clear, the question posed is about the choice of person against whom enforcement is made (in this case the person to whom the injunction was addressed and whose bank assets were attached, Kentriko Zagori). I make no conclusions here about the potential addressees of Commission acts referred to in the first paragraph of Article 299 TFEU. Whether or not the Commission could have addressed its decision to the shareholder of the undertaking (or the municipality into which it was subsequently integrated) and the legal basis for the choice of addressee is a hypothetical question and outside the scope of the request for reference.

77. Whether or not enforcement can be made against a person different from the one to whom the Commission Decision is addressed is then a question for national law, in accordance with the principle of national procedural autonomy.

78. However, in accordance with the case-law cited above in footnote 15, national procedural autonomy is in turn subject to the principles of equivalence and effectiveness.

79. In this regard, the Commission pleads that, in order to respect the principles of equivalence and effectiveness, it must be allowed to enforce its decision against Dimos Zagoriou. ( 34 ) It argues in substance that the relevant Greek rules allow municipalities to take over all the assets of (dissolved) municipal undertakings and to ‘cherry pick’ the debts. However, there is an exception as regards succession to certain debts owed to the Greek State and social security organisms, which is compulsory. Thus, debts vis-à-vis the Greek State and social security organisms receive preferential treatment.

80. According to the Commission, to the extent succession by Dimos Zagoriou to the undertaking’s debt towards the EU is excluded as a result of those national rules, application of Article 299 TFEU is rendered impossible or excessively difficult and the principle of effectiveness is thus compromised. To the extent the succession by Dimos Zagoriou to debts owed to the Greek State and social security organisms are ensured but those owed to the EU are not, the principle of equivalence is compromised.

81. The assessment of whether the principles of equivalence and effectiveness are respected in this case is ultimately one for the referring court. Any guidance that the Court can give is in this case hampered by the fact that the request for a preliminary ruling does not give any detail on the rules of succession that the Commission and Dimos Zagoriou refer to in their pleadings. Nonetheless, in order to assist the referring court in its assessment, I would make the following observations.

(a) Article 299 TFEU and national rules of succession

82. By way of preliminary remark, it could be questioned whether the rules on succession of liability can be made the subject of an assessment under the principles of equivalence and effectiveness. It is indeed unclear precisely what type of rules those principles apply to.

83. The dual requirement of equivalence and effectiveness were developed in the case-law as a limit to national procedural autonomy. They are indeed applied very often in that context. They assess the equivalence and effectiveness of procedural treatment through the application of similar procedural rules. However, they are also frequently expressed as more broadly placing limits on judicial and remedial autonomy ( 35 ) and also in relation to clearly non-procedural or remedial rules. ( 36 ) Obvious examples include their application to causation, ( 37 )contractual consequences of non-compliance with a Directive, ( 38 ) and choice of competent organs. ( 39 ) That raises the question of whether the principles can be applied to rules on succession, which could be seen as purely substantive rules of law, at least in some national systems.

84. In my view, acknowledging the gradual evolution of the case-law in this area, the dual requirement of equivalence and effectiveness can nowadays be said to apply ‘horizontally’ to any legislative choices made by the Member States in terms of remedies and enforcement of EU law at the national level, in the absence of EU rules. For that reason, I consider the principles could at least potentially be applied to rules of succession.

85. That said, I do have a fundamental concern with their application to the rules of succession in this case. Simply put, those rules appear to me to be too remote to be successfully contested under the principles of equivalence and effectiveness. Notwithstanding their generally broad applicability as discussed in the preceding paragraph, there must be a clear connection between the original EU law-based right or obligation and the specific national rule that hampers its realisation on the national level in concrete cases. Those principles are not and should not become a ‘golden ticket’ to challenge any and every procedural and substantive rule of national law which simply does not fit, however remote it may be from the scope of the original obligation. ( 40 )

86. Article 299 TFEU is a provision relating to enforcement of acts imposing a pecuniary obligation. One could therefore reasonably expect that the national rules that fall within its scope are those relating to the enforcement of such acts before the responsible national authorities. However, from there, to suddenly reach into the substantively unrelated national rules on the succession of debts in the context of dissolution of undertakings and fusion of municipalities appears to be a very far stretch.

87. I would therefore suggest that in the context of the present case, the dual requirement of equivalence and effectiveness, if examined in the context of the national realisation of Article 299 TFEU, simply does not cover national rules on the succession of debts in the context of dissolution of undertakings and fusion of municipalities.

88. Should the Court nonetheless conclude that the principles of equivalence and effectiveness may apply in this case in relation to the national rules on succession, I shall also offer suggestions on the application of both principles to questions 3 and 4. From the point of view of equivalence, the main challenge is establishing valid comparability of proceedings and treatment in relation to such a specific aspect of enforcement. From the point of view of effectiveness, it is questionable whether such a remote rule can render EU law-based claims ‘impossible or excessively difficult’.

89. I shall consider each of the principles in more detail below.

(b) Principle of equivalence

90. As regards the principle of equivalence, the Commission’s argument is essentially that it should be treated in the same way as the Greek State ( 41 ) for the purposes of applying rules of succession, in the context of enforcement actions for recovery of debt.

91. The fundamental weakness I see in that argument is that the principle of equivalence is not used to compare legal persons, or states and institutions, and the treatment they receive. It is not about equal treatment of creditors. ( 42 ) Instead, the principle of equivalence is about ensuring comparable treatment of proceedings, with a view to ensuring EU law is applied. It requires that EU law-based claims are not treated any less favourably than similar national law-based claims. ( 43 )

92. However, to the extent the Commission’s argument can be interpreted as attempting to compare proceedings, as explained above in points 25 and 38 to 41, it is for the referring court to determine whether proceedings are similar, on the basis of their purpose, cause of action and essential characteristics. In doing so, the referring court may take into account the fact that the enforcement at issue in the main case results from the exercise by the Commission of special powers distinct from the normal rules applicable in relations between private individuals. In that regard, I refer to the reasoning already set out above in point 54.

93. Once the referring court has identified similar proceedings, it must assess similarity of rules and determine whether there is indeed unfavourable treatment of EU law-based claims, as the Commission alleges. In that regard, it is obviously important to be clear on the precise nature of the rule being invoked and assessed in the light of the principle of equivalence.

(c) Principle of effectiveness

94. A national rule may breach the principle of effectiveness if it makes the exercise of EU law rights impossible or excessively difficult. Without being contradicted by the Commission, it has been argued by Dimos Zagoriou that the undertaking actually still exists and even owns assets, which are held by a bank. To the extent that is indeed the case, and the Commission could have or still can recover in full the aid from the undertaking, I do not consider that there can be any breach of the principle of effectiveness.

95. The undertaking’s continued existence and ownership of assets is a factual point for the national court to verify. However, to the extent that it does exist and possesses assets, as alleged by the Dimos Zagoriou, I would add the following in relation to the principle of effectiveness.

96. If relevant national rules on succession foresee the possibility for a public authority, which controls a company that has wrongly received EU aid, to liquidate that company and basically transfer all its assets including the aid to itself, while having the discretion to renounce any liabilities of the company it chooses, then indeed such a scenario could raise issues under the principle of effectiveness.

97. While that appears to be the thrust of the Commission’s allegation, I do not know whether such a scenario corresponds in any way to the rules applicable at national level in the main case. Indeed, at least on the basis of the written and oral pleadings submitted to the Court, there is disagreement about the material, personal and temporal application of those rules. As a result, in my opinion, the Court simply does not have the necessary elements to be in a position to give any detailed guidance in that regard.

98. Two other points raised during the proceedings before the Court merit attention here, namely the relevance of the EU State aid law and the principles of loyal cooperation and effective judicial protection. I will consider these below under (d) and (e).

(d) State aid and loyal cooperation

99. In its written pleadings, the Commission agrees that national law determines the identity of the person against whom enforcement of a Commission decision imposing a pecuniary obligation should be sought. However, the Commission adds that analogous application of the rules of succession under EU State aid law — inspired, in particular, by the Roman law actio pauliana ( 44 ) — also pleads in favour of the Commission being able to hold Dimos Zagoriou jointly and severally liable for the debts of the undertaking. The Commission also draws inspiration in that regard from the EU law principle of loyal cooperation.

100. Whilst credit is certainly due for argumentative inventiveness, I consider that regard must be had here to the rule of law and the EU law principle of legal certainty, which is arguably of equally august ancestry. ( 45 )

101. Article 299 TFEU makes it explicit that enforcement is a question for national law. Invoking analogies with EU State aid rules — which are an entirely separate set of legal rules — goes against the clear wording of that provision. It also flies in the face of legal certainty. As confirmed by this Court ‘the principle of legal certainty requires that rules imposing charges on the taxpayer must be clear and precise so that he may know without ambiguity what are his rights and obligations and may take steps accordingly’. ( 46 ) The same applies, a fortiori, when it comes to enforcing demands for payment against third parties. The legal basis for such enforcement must be clear. I recall that the Commission confirmed that it had invoked no provision of secondary EU law to justify succession.

102. As regards the principle of loyal cooperation, the Commission makes little more than a passing reference to it. I do not consider that sufficient to begin imputing debts to third parties, where no specific legal basis under EU or national law foresees that possibility.

103. I might only add that the obligation of loyal cooperation cuts both ways. It also requires due diligence on the part of the EU institutions. In that respect, I recall that the Commission did not adopt the decision seeking repayment of the aid until 2006, that is, six years after it was informed that the project in relation to which the aid was granted would not go ahead. ( 47 ) Had the Commission acted in a more timely fashion to protect the financial interests of the Union, it would perhaps not now need to resort in its pleadings to rather novel analogies with State aid law and the principle of equivalence and effectiveness against third parties in order to do so. ( 48 )

(e) Effective judicial protection

104. A final issue that has not been explicitly raised by the national court but which was discussed at the oral hearing and deserves a concluding remark is the effective judicial protection of the Dimos Zagoriou. In that regard, neither Dimos Zagoriou nor Kentriko Zagori were addressees of the Commission Decision and in principle could not have challenged it directly under Article 263 TFEU. ( 49 ) The question that arises is whether the entity against which the Commission Decision is being enforced must have the possibility of challenging the legality of that decision when it was addressed to another entity?

105. The implication of that question is clear: if the EU law principle of effective judicial protection requires that any entity, against which enforcement of a decision under Article 299 TFEU is sought, must be able to challenge that decision, and Kentriko Zagori (now Dimos Zagoriou) could not, then enforcement could not be sought against it as a matter of EU law.

106. To that extent, the point is relevant in the context of the referring court’s third and fourth questions, which in substance asks whether EU or national law determines the circle of entities against which enforcement can be sought and whether they include Kentriko Zagori and/or Dimos Zagoriou. If the EU law principle of effective judicial protection does influence that circle of entities, then it arguably needs to be addressed here.

107. However, it is also the case that the point was not explicitly raised by the referring court and it is not clear that Kentriko Zagori or Dimos Zagoriou has ever questioned the legality of the Commission Decision. For that reason, and although the topic of effective judicial protection was indeed discussed at the oral hearing, this particular line of enquiry is, in my opinion, hypothetical.

108. Should the Court nonetheless choose to address that specific point, I would make the following brief remarks.

109. First, it is to my mind obvious as a general proposition that, if an EU institution seeks to seize a person’s assets, that person should in principle have the right to question the legality of the seizure on the merits. Since the Pandora’s box of legal Latin is already open: ubi jus ibi remedium.

110. Second, how that general proposition translates into situations involving succession is less clear. Thus, I can well imagine situations where a person succeeds to the debt of another but — possibly quite legitimately — cannot challenge that debt. ( 50 ) Such considerations already bring one into contact with potentially complex questions of national law and the mechanics of succession. Again, in my view, the Court lacks the necessary information to make any detailed observations on how the EU principle of effective judicial protection would apply in practice in such a context.

111. Third, neither Kentriko Zagori nor Dimos Zagoriou could have challenged the Commission Decision under Article 263 TFEU or directly before national courts, which do not have the competence to invalidate EU acts. ( 51 ) It is less clear whether either one could have challenged the Commission Decision indirectly by requesting a preliminary reference on validity in the context of national enforcement proceedings ( 52 ) or, if it could have, the appropriateness and adequacy of using the preliminary reference route to challenge the Commission Decision. As important as those questions are, they are not, however, the subject matter of the present case.

(f) Conclusion

112. In the light of the foregoing, I propose to answer to the referring court’s third and fourth questions as follows: In case of enforcement of an act, adopted pursuant to Regulations No 2052/88, No 4253/88 and No 4256/88 and Article 299 TFEU, and imposing a pecuniary obligation on an undertaking owned by a local authority, which undertaking has subsequently been dissolved, Article 299 TFEU and the aforementioned EU regulations do not require that local authority to discharge the pecuniary obligation imposed on the undertaking. It is for national law to determine the persons against whom enforcement can be sought, subject to the principles of equivalence and effectiveness.

V. Conclusion

113. In the light of the above, I propose that the Court respond to the questions posed by the Monomeles Efeteio Athinon (Court of Appeal of Athens (single judge)) as follows: Questions 1 and 2 It is for national law, subject to the principles of equivalence and effectiveness, to determine which courts have jurisdiction to hear actions opposing the enforcement of acts of the European Commission which impose a pecuniary obligation on persons other than Member States, pursuant to Article 299 TFEU. In determining whether there is any breach of the principle of equivalence, the national court must, first, ascertain whether the proceedings concerned are similar as regards their purpose, cause of action and essential characteristics, and second, examine whether the procedural rules for the actions based on EU law are less favourable than those for the actions based exclusively on national law. Questions 3 and 4 In case of enforcement of an act, adopted pursuant to Council Regulations (EEC) No 2052/88 of 24 June 1988 on the tasks of the Structural Funds and their effectiveness and on coordination of their activities between themselves and with the operations of the European Investment Bank and the other existing financial instruments, (EEC) No 4253/88 of 19 December 1988, laying down provisions for implementing Regulation No 2052/88 and (EEC) No 4256/88 of 19 December 1988, laying down provisions for implementing Regulation No 2052/88 as regards the EAGGF Guidance Section and Article 299 TFEU, and imposing a pecuniary obligation on an undertaking owned by a local authority, which undertaking has subsequently been dissolved, Article 299 TFEU and the aforementioned EU regulations do not require that local authority to discharge the pecuniary obligation imposed on the undertaking. It is for national law to determine the persons against whom enforcement can be sought, subject to the principles of equivalence and effectiveness.

( 1 ) Original language: English.

( 2 ) Commission Decision C(2006) 4798.

( 3 ) Council Regulation of 24 June 1988 on the tasks of the Structural Funds and their effectiveness and on coordination of their activities between themselves and with the operations of the European Investment Bank and the other existing financial instruments (OJ 1988 L 185, p. 9).

( 4 ) Council Regulation of 19 December 1988, laying down provisions for implementing Regulation (EEC) No 2052/88 as regards coordination of the activities of the different Structural Funds between themselves and with the operations of the European Investment Bank and the other existing financial instruments (OJ 1988 L 374, p. 1).

( 5 ) Council Regulation of 19 December 1988, laying down provisions for implementing Regulation (EEC) No 2052/88 as regards the EAGGF Guidance Section (OJ 1988 L 374, p. 25).

( 6 ) See footnote 2.

( 7 ) According to the written pleadings of Dimos Zagoriou this happened pursuant to a law adopted in 1997 (Law 2359/1997).

( 8 ) According to the written pleadings of Dimos Zagoriou this happened in 2005. However, it would appear that the process was still ongoing and that the undertaking still existed at the time of the reference.

( 9 ) According to the written pleadings of Dimos Zagoriou this happened pursuant to a law adopted in 2010 (Law 3852/2010).

( 10 ) Judgment of 16 June 2015, Gauweiler and Others (C‑62/14, EU:C:2015:400, paragraph 25).

( 11 ) Judgment of 13 July 2006, Manfredi and Others (C‑295/04 to C‑298/04, EU:C:2006:461, paragraph 70).

( 12 ) Strictly speaking, the Commission Decision refers to, and enforcement was originally sought under, Article 256 EC. Other than necessary updates that provision is identical to Article 299 TFEU (the new wording of the article refers to ‘acts’ as opposed to ‘decisions’ of the Council, Commission and the European Central Bank). As a result, there is no need to address here any issues of temporal scope of application and I will refer to Article 299 TFEU, as the referring court does in its question.

( 13 ) In the sense of innovative, rather than new, since it has been in the Treaty since 1957.

( 14 ) Other than verification of authenticity of the decision.

( 15 ) See, on that point in relation to choice of courts, judgments of 24 April 2008, Arcor (C‑55/06, EU:C:2008:244, paragraph 170), and of 12 February 2015, Baczó and Vizsnyiczai (C‑567/13, EU:C:2015:88, paragraphs 43 to 47).

( 16 ) However, the point requires more attention in the context of the referring court’s third and fourth questions.

( 17 ) Prechal, S., and Cath, K., ‘The European acquis of Civil Procedure: Constitutional aspects’, Uniform Law Review, Vol. 19, Oxford University Press, 2014, p. 182.

( 18 ) Judgment of 1 December 1998, Levez (C‑326/96, EU:C:1998:577, paragraph 43).

( 19 ) Judgments of 27 June 2013, Agrokonsulting-04 (C‑93/12, EU:C:2013:432, paragraph 39), and of 12 February 2015, Baczó and Vizsnyiczai (C‑567/13, EU:C:2015:88, paragraph 44).

( 20 ) Judgment of 16 May 2000, Preston and Others (C‑78/98, EU:C:2000:247, paragraph 63).

( 21 ) Judgments of 26 January 2010, Transportes Urbanos y Servicios Generales (C‑118/08, EU:C:2010:39, paragraph 33), and of 8 July 2010, Bulicke (C‑246/09, EU:C:2010:418, paragraph 26).

( 22 ) Judgment of 12 February 2015, Baczó and Vizsnyiczai (C‑567/13, EU:C:2015:88, paragraph 45).

( 23 ) See above in footnotes 18 and 19.

( 24 ) I shall return to that issue further below in points 104 to 111.

( 25 ) Applicable, of course, only to obligations of pecuniary nature, such as fines, or for example, the obligation of the convicted person to pay damages to the victim of a crime if that obligation was pronounced by a criminal court.

( 26 ) Judgment of 1 December 1998, Levez (C‑326/96, EU:C:1998:577, paragraph 43).

( 27 ) See on this issue, for example, Reich, N., ‘The Public/Private Divide in European Law’, European Private Law after the Common Frame of Reference, Edward Elgar Publishing, Cheltenham 2010, pp. 56 to 89.

( 28 ) For a comparative discussion in relation to France and the UK, see, for example, ‘The Public Law/Private Law Divide: une entente assez cordiale?’, La distinction du droit public et du droit privé: regards français et britanniques, edited by Auby, J.B., and Freedland, M., Hart Publishing, 2006.

( 29 ) See, by analogy, the Court’s case-law on the concept of State for the purpose of determining the direct effect of directives (judgment of 12 July 1990, Foster and Others (C‑188/89, EU:C:1990:313, paragraph 20). See also the case-law on the scope of application of Regulation (EU) No 1215/2012 of the European Parliament and of the Council of 12 December 2012 on jurisdiction and the recognition and enforcement of judgments in civil and commercial matters (OJ 2012 L 351, p. 1) which does not apply to revenue, customs or administrative matters or to the liability of the State for acts and omissions in the exercise of State authority (acta iure imperii). See also judgment of 9 September 2015, Lito Maieftiko Gynaikologiko kai Cheirourgiko Kentro v Commission (C‑506/13 P, EU:C:2015:562, paragraph 20), where the Court distinguished normal contractual relationships entered into by the Commission from those involving the ‘exercise of the prerogatives of a public authority conferred on the contracting institution acting in its capacity as an administrative authority’.

( 30 ) Judgment of 16 May 2000, Preston and Others (C‑78/98, EU:C:2000:247, paragraph 63).

( 31 ) Judgment of 12 February 2015, Baczó and Vizsnyiczai (C‑567/13, EU:C:2015:88, paragraph 46).

( 32 ) In its order for reference, the national court uses the term ‘capacity to be made a defendant’ of the ‘person liable’. I understand that by ‘person liable’ what is intended is ‘person against whom enforcement is sought’, namely the municipality, not the undertaking.

( 33 ) In its written pleadings the Commission does however make an analogy with EU State aid rules of succession and refers to the principle of loyal cooperation. I will return to these below in points 99 to 103.

( 34 ) The Commission only refers in its written pleadings to Dimos Zagoriou, not Kentriko Zagori. As explained above, the Commission Decision was actually already enforced against Kentriko Zagori but the latter was integrated into Dimos Zagoriou.

( 35 ) See in this sense, for example, judgment of 24 April 2008, Arcor (C‑55/06, EU:C:2008:244, paragraph 170), referring to application of the principles to ‘the competent court, the nature of the dispute and, consequently, the detailed rules of judicial review’.

( 36 ) See in this regard for example Prechal, S., and Cath, K., The European acquis of Civil Procedure: Constitutional aspects, pp. 180 to 181.

( 37 ) Judgment of 20 October 2011, Danfoss and Sauer-Danfoss (C‑94/10, EU:C:2011:674).

( 38 ) Judgments of 6 June 2002, Sapod Audic (C‑159/00, EU:C:2002:343), and of 30 May 2013, Genil 48 and Comercial Hostelera de Grandes Vinos (C‑604/11, EU:C:2013:344).

( 39 ) See case-law cited above in footnote 15 in relation to designation of competent courts.

( 40 ) By analogy, the Court has also recently held for example that, even in spite of the arguably much more explicit provision of Article 8 of Directive 2008/94/EC, which requires that ‘Member States shall ensure that the necessary measures are taken to protect the interest of employees … at the date of the onset of the employer’s insolvency’ (Directive of the European Parliament and of the Council of 22 October 2008 on the protection of employees in the event of the insolvency of their employer (OJ 2008 L 283, p. 36)), that provision cannot be stretched so far as to require changes in national insolvency rules to the effect that payments due by the employer were to be ring-fenced and excluded from the insolvency proceedings. See judgment of 24 November 2016, Webb-Sämann (C‑454/15, EU:C:2016:891).

( 41 ) The Commission also compares its treatment to that of social security organisms.

( 42 ) There are specific rules that do require ‘equal treatment’ of the EU and Member State public authorities as creditors, but none appear relevant or have been invoked in the present case. For example, Article 82 of the Financial Regulation in its current version, which provides that ‘in the event of insolvency proceedings, Union entitlements shall be given the same preferential treatment as entitlements of the same nature due to public bodies in the Member States where the recovery proceedings are being conducted’ (Regulation (EU, Euratom) No 966/2012 of the European Parliament and of the Council of 25 October 2012 on the financial rules applicable to the general budget of the Union and repealing Council Regulation (EC, Euratom) No 1605/2002 (OJ 2012 L 298, p. 1)).

( 43 ) It is indeed perhaps the remoteness of the rules of succession and the resulting difficulties of comparing proceedings that led the Commission in this case to fall back on what seems to me more a comparison of treatment of creditors than of claims. See above, points 85 to 87.

( 44 ) That is, a legal remedy governed by civil law which protects creditors against disposals of assets made by their debtors with the intention to defraud (see Opinion of Advocate General Ruiz-Jarabo Colomer in Deko Marty Belgium (C‑339/07, EU:C:2008:575, points 23 to 29), which also evokes the even older, more colourful and hands-on ‘actio per manus iniectio’, which by contrast has not been invoked by the Commission). I shall assume that the Commission refers, as far as it is in fact possible, generally to a legal instrument of Roman law, without in any way intimating that the type of scenario that gave birth to that legal institution (namely fraud to the detriment of the creditors) is present in this case as well.

( 45 ) The Oxford Handbook of Roman Law and Society, edited by Du Plessis, P.J., Ando, C., and Tuori, Kaius, Oxford University Press, Oxford, 2016, pp. 25 to 26.

( 46 ) Judgments of 9 July 1981, Gondrand and Garancini (169/80, EU:C:1981:171, paragraph 17), and of 23 September 2003, BGL (C‑78/01, EU:C:2003:490).

( 47 ) The Commission also confirmed at the oral hearing that it failed to file its defence to Kentriko Zagori’s opposition action in good time.

( 48 ) See, on the importance of parties showing diligence in exercising their legal rights, judgment of 24 March 2009, Danske Slagterier (C‑445/06, EU:C:2009:178, paragraphs 61 to 64).

( 49 ) Even if in theory Kentriko Zagori would have had standing to challenge the Commission Decision, enforcement was sought against Kentriko Zagori well after the two-month deadline for challenging it under Article 263 TFEU had expired.

( 50 ) For example, the universal successor to an estate may inherit tax and other debts which have been outstanding for some time and can no longer be challenged.

( 51 ) Judgment of 22 October 1987, Foto-Frost (314/85, EU:C:1987:452).

( 52 ) See by analogy judgment of 18 February 2016, Finanmadrid EFC (C‑49/14, EU:C:2016:98, paragraph 55), which also concerned the possibility of raising of pleas on the merits in the context of enforcement proceedings. See more generally as regards use of the preliminary ruling mechanism to challenge the legality of EU measures underlying national acts: judgments of 15 June 1976, Frecassetti (113/75, EU:C:1976:89, paragraphs 8 and 9); of 13 December 1989, Grimaldi (C‑322/88, EU:C:1989:646, paragraph 8); and of 8 March 2007, Roquette Frères (C‑441/05, EU:C:2007:150, paragraphs 39 and 40).