1. By order of 5 May 1993, received at the Court on 14 May 1993, the Arbeitsgericht Bremen (Bremen Labour Court) referred to the Court for a preliminary ruling under Article 177 of the EEC Treaty three questions on the interpretation of Article 119 of the EEC Treaty and of Council Directive 75/117/EEC of 10 February 1975 on the approximation of the laws of the Member States relating to the application of the principle of equal pay for men and women (OJ 1975 L 45, p. 19, hereinafter " the Directive" ).
2. Those questions were raised in proceedings between Edith Freers and Hannelore Speckmann (hereinafter " the plaintiffs" ) and Deutsche Bundespost (hereinafter " the defendant" ) concerning compensation for the time spent by the plaintiffs on a training course which was necessary for the performance of their staff committee functions but which took place outside their individual working hours.
3. The plaintiffs are employed part-time by the defendant for 18 hours a week. As members of the staff committee (Personalrat), they attended a training course from 9 to 14 February 1992 which lasted for approximately 38.5 hours, which are the weekly working hours laid down for full-time employees in the collective agreement.
4. During the training course the defendant continued to pay the plaintiffs their normal wages calculated on the basis of their part-time work. Relying on the German legislation, it did not, however, give them any additional pay, nor did it offer them paid leave in respect of the time spent on the course outside their normal working hours.
5. Staff committees in Federal administrative bodies, which include the defendant, are subject to the Bundespersonalvertretungsgesetz (Law on Federal staff representation, hereinafter " the BPersVG" ) of 15 March 1974 (BGBl. I, p. 693) in the version of 16 January 1991 (BGBl. I, p. 47).
6. Paragraph 46(1), (2), (5) and (6) of the BPersVG provides: " 1. The members of the staff committee shall perform their functions as an unpaid honorary office. 2. Where it is necessary for the proper performance of staff committee functions for members to miss working hours, this shall not entail any reduction of salary or wages. If staff committee members are required to spend longer than their normal working hours to perform their functions, they shall be given corresponding time off. ... 5. Staff committee members who are entirely exempted from their work duties shall receive a monthly compensation for the time spent. Members who are partially so exempt, provided that it is for at least half of the normal working hours, shall receive half of the compensation referred to in the first sentence. The amount of the compensation shall be fixed by the Federal Government by regulation which does not require the approval of the Bundesrat. 6. The members of the staff committee are to be exempted from work duties, without loss of pay, in order to attend training courses providing them with the knowledge necessary for their staff committee functions. "
7. The wording of that provision is similar to that of Paragraph 37 of the Betriebsverfassungsgesetz (Industrial Relations Law, hereinafter " the BetrVG" ) of 15 January 1972 (BGBl., p. 13) in the version of 23 December 1988 (BGBl. 1989, p. 1, correction on p. 902), as amended by the law of 18 December 1989 (BGBl. I, p. 2386), relating to staff councils (Betriebsrat).
8. Paragraph 37(1), (2), (3) and (6) provides: " 1. The members of the staff council shall perform their functions as an unpaid honorary office. 2. Staff council members shall be released without loss of pay from their employment obligations if and in so far as the size and nature of the undertaking make such release necessary in order to perform their duties properly. 3. As compensation for staff council work which, for reasons connected with the undertaking, takes place outside working hours, staff council members shall be entitled to a corresponding amount of paid leave. The leave shall be granted within one month; if for reasons connected with the undertaking that is not possible, the time spent shall be paid as overtime. ... 6. Subparagraph 2 shall apply mutatis mutandis to attendance at training courses which provide knowledge necessary for the staff council ' s work. The staff council shall take account of the undertaking ' s requirements in determining the time for participation at training courses. It shall inform the employer in good time of participation in and times of training courses. If the employer considers that insufficient account has been taken of the undertaking ' s requirements, he can refer the matter to the conciliation body. The conciliation body ' s decision shall take the place of agreement between the employer and the staff council. "
9. The order for reference indicates that Paragraph 46 of the BPersVG and Paragraph 37 of the BetrVG have been interpreted by the Bundesarbeitsgericht (Federal Labour Court) and the Bundesverwaltungsgericht (Federal Administrative Court) as meaning that staff committee members and staff council members are not entitled to paid leave and compensation for attendance at training courses outside their normal working hours.
10. In Case C-360/90 Arbeiterwohlfahrt der Stadt Berlin v Bötel [1992] ECR I-3589 the Court held that Article 119 of the EEC Treaty and the Directive preclude national legislation applicable to a much greater number of women than men from limiting to their individual working hours the compensation, in the form of paid leave or overtime pay, which staff council members employed on a part-time basis are to receive from their employer for attending training courses which impart the knowledge necessary for working on staff councils and are held during the full-time working hours applicable in the undertaking but which exceed their own part-time working hours, when staff council members employed on a full-time basis are compensated for attendance of the same courses on the basis of full-time working hours.
11. The Court stated, however, that it remains open to the Member State to prove that such legislation is justified by objective factors unrelated to any discrimination on grounds of sex.
12. The national court considers that the judgment in Bötel does not take account of the special features of the system of staff committees in German law and calls into question the principle of unpaid honorary office, which is intended to guarantee the independence of staff committee members.
13. In those circumstances the Arbeitsgericht Bremen stayed the proceedings and referred the following questions to the Court for a preliminary ruling: " 1. Does the economic compensation accorded to a male or female employee in respect of work on a statutorily established employee representation body constitute pay within the meaning of the European provisions on equal pay for men and women (Article 119 of the EEC Treaty and Council Directive 75/117/EEC of 10 February 1975)? 2. If the answer to Question 1 is yes: Does the fact that under national law work on an employee representation body is unpaid, being governed essentially by the loss-of-pay principle ( Lohnausfallprinzip ), constitute an objective ground for unequal treatment which is in no way connected with discrimination against women? 3. If the answer to Question 2 is no: Is it an objective ground for unequal treatment of this kind that whereas part-time employees continue to receive pay in respect of their attendance at an all-day training course only in accordance with their part-time working hours, employees who normally work overtime are paid for that overtime even if the duration of the training course corresponds to that of the normal working day? " Question 1
14. The German Government considers that the compensation referred to in the provisions in question does not constitute pay within the meaning of Article 119 of the EEC Treaty. Staff committee functions are performed on an unpaid honorary basis and the compensation received is intended only to make good the loss of earnings suffered by staff committee members when staff representation functions or information or training courses needed for the proper performance of those functions take place during working hours.
15. The German Government considers, moreover, that the fact that staff representation functions are in the general interest of the employer is not enough to give the compensation for those functions the character of pay. The essence of the function of staff committees is to represent the staff.
16. It must be observed first of all that legal concepts and definitions established or laid down by national law cannot affect the interpretation or binding force of Community law, or, consequently, the scope of the principle of equal pay for men and women laid down in Article 119 of the Treaty and in the Directive and developed by the Court ' s case-law (see, most recently, Case C-457/93 Kuratorium für Dialyse und Nierentransplantation v Lewark [1996] ECR I-0000, paragraph 20).
17. It is settled law that the concept of " pay" within the meaning of Article 119 of the Treaty comprises any consideration, whether in cash or in kind, whether immediate or future, provided that the worker receives it, albeit indirectly, in respect of his employment from his employer, and irrespective of whether the worker receives it under a contract of employment, by virtue of legislative provisions or on a voluntary basis (see Lewark , paragraph 21, and Case C-262/88 Barber v Guardian Royal Exchange Assurance Group [1990] ECR I-1889, paragraph 12).
18. As the Court held in Bötel , paragraph 14, although compensation such as that at issue in the main proceedings does not derive as such from the contract of employment, it is nevertheless paid by the employer by virtue of legislative provisions and under a contract of employment. Staff committee members must necessarily be employees of the undertaking, to be able to serve on that undertaking ' s staff committee.
19. It follows that compensation received for loss of earnings due to attendance at training courses imparting the information necessary for performing staff committee functions must be regarded as pay within the meaning of Article 119 and the Directive, since it constitutes a benefit paid indirectly by the employer by reason of the existence of an employment relationship.
20. Consequently, the compensation paid to a male or female worker for taking part in statutorily established staff representation constitutes pay within the meaning of Article 119 of the EEC Treaty and the Directive. Questions 2 and 3
21. By its second and third questions the national court essentially asks whether Article 119 of the EEC Treaty and the Directive preclude national legislation which limits to their individual working hours the compensation which staff committee members employed on a part-time basis are to receive from their employer for attending training courses which impart the knowledge necessary for serving on staff committees and are held during the full-time working hours applicable in the undertaking but which exceed their individual part-time working hours, when staff committee members employed on a full-time basis receive compensation for attendance at the same courses on the basis of their full-time working hours.
22. It must be observed first that the exclusion of part-time workers from certain benefits is in principle contrary to Article 119 of the Treaty if it is the case that a much higher proportion of women than men work part-time. It would be otherwise only if the difference of treatment found to exist was justified by objective factors unrelated to any discrimination based on sex.
23. The Court held in Bötel and Lewark , with reference to national provisions similar to those at issue in the main proceedings, firstly that in principle they caused discrimination against women workers, contrary to Article 119 of the Treaty and the Directive, and secondly that it remained open to the Member State to prove that the legislation was justified by objective factors unrelated to any discrimination on grounds of sex.
24. It is settled law that although in preliminary-ruling proceedings it is for the national court to establish whether such objective factors exist in the particular case before it, the Court of Justice, which has to provide answers of use to the national court, may provide guidance based on the documents before the national court and on the written and oral observations which have been submitted to it, in order to enable the national court to give judgment (see, inter alia , Case C-328/91 Secretary of State for Social Security v Thomas and Others [1993] ECR I-1247, paragraph 13).
25. The German Government observes that, if there were a difference of treatment, it would be justified by the principle that staff committee members are not paid, which is intended to ensure their independence. The unpaid nature of staff committee functions and the principle that they must not confer any benefit or entail any disadvantage have the purpose of ensuring members ' independence. They thus ensure that the decision to stand for election to a staff committee is guided by concerns of the general interest and not by the wish to obtain a financial benefit.
26. Moreover, it is also apparent from the Lewark judgment, cited above, that the Bundesarbeitsgericht considered, with respect to similar provisions on staff councils, that the German legislature ' s wish to place the independence of staff council members above financial inducements for performing staff council functions, as expressed in the provisions at issue, was an aim of social policy.
27. Such an aim appears in itself to be unrelated to any discrimination on grounds of sex. It cannot be disputed that the work of staff committees does indeed promote harmonious labour relations within undertakings, in particular by ensuring that the workers ' interests are represented. The concern to ensure the independence of the members of those committees thus likewise reflects a legitimate aim of social policy.
28. If a Member State is able to show that the measures chosen reflect a necessary aim of its social policy and are suitable and necessary for achieving that aim, the mere fact that the legislative provision affects far more women workers than men cannot be regarded as a breach of Article 119 and the Directive (see Case C-343/92 De Weerd, née Roks, and Others v Bestuur van de Bedrijfsvereniging voor de Gezondheid, Geestelijke en Maatschappelijke Belangen and Others [1994] ECR I-571 and Case C-444/93 Megner and Scheffel v Innungskrankenkasse Vorderpfalz [1995] ECR I-0000).
29. It is for the national court to ascertain, in the light of all the relevant factors and taking into account the possibility of achieving the social policy aim in question by other means, whether the difference of treatment in question is suitable and necessary for achieving that aim.
30. In so doing the national court must bear in mind that, as the Court held in Bötel , paragraph 25, legislation such as that at issue is likely to deter workers in the part-time category, in which the proportion of women is undeniably preponderant, from performing staff committee functions or from acquiring the knowledge necessary for performing them, thus making it more difficult for that category of worker to be represented by qualified staff committee members.
31. Consequently, where the category of part-time workers includes a much higher number of women than men, the prohibition of indirect discrimination in the matter of pay, as set out in Article 119 and in the Directive, precludes national legislation which, not being suitable and necessary for achieving a legitimate social policy aim, has the effect of limiting to their individual working hours the compensation which staff committee members employed on a part-time basis are to receive from their employer for attending training courses which impart the knowledge necessary for serving on staff committees and are held during the full-time working hours applicable in the undertaking but which exceed their individual part-time working hours, when staff committee members employed on a full-time basis receive compensation for attendance at the same courses on the basis of their full-time working hours.