OPINION OF ADVOCATE GENERAL

LENZ

delivered on 14 July 1993 ( *1 )

Mr President,

Members of the Court,

A — Introduction

1. The reference by the Court of Appeal for a preliminary ruling in this case is concerned with the interpretation and application of the principle of equal pay for men and women laid down in Article 119 of the EEC Treaty. The Court of Appeal has summarized the relevant facts as follows: ‘1. The complainant who is a woman does job A in a profession (speech therapy) in which the staff employed by the employer X arc almost all women and in which the holders of job A are almost all women. 2. The comparator who is a man does job B in a profession (pharmacy) in which a majority of the staff employed by the employer X are female but where the majority of the holders of job B are men. 3. Job A and job B are different but are assumed for the purpose of these proceedings to be of equal value in terms of the demands they make upon the job holder. 4. Employees doing job B receive higher remuneration than employees doing job A. 5. The rates of pay for the two professions (including the rates of pay for job A and job B) arc and have been determined by collective bargaining between the employer and the representative trade unions. 6. The same trade union (and the same trade union representative) represents the two professions and the collective bargaining in relation to the pay of speech therapists (including employees in job A) is carried out separately and independently from the collective bargaining in relation to pharmacists (including employees in job B). 7. It has been determined by the tribunal of fact that there has been no sex discrimination whether direct or indirect intentional or unintentional in the manner in which the collective bargaining processes (considered separately) have been carried out or in regard to the arrangements for entry or transfer into or promotion within either of the two professions. 8. Despite the absence of sex discrimination in the sense explained in paragraph 7 the system of separate collective bargaining for the two professions has and has had an adverse impact in practice on women in that holders of job A (who are almost all women) receive lower pay than holders of job B (who are mainly men) although the work of job A is of equal value to the work of job B. 9. The employer has established that part (being more than a de minimis part) but not the whole of the difference in pay between jobs A and B is objectively justified by reason of a shortage of suitably qualified pharmacists.’

2. The Court of Appeal then asked the Court of Justice the following questions: ‘Question 1: Does the principle of equal pay enshrined in Article 119 of the Treaty of Rome require the employer to justify objectively the difference in pay between job A and job B? Question 2: If the answer to question 1 is in the affirmative can the employer rely as sufficient justification for the difference in pay upon the fact that the pay of jobs A and B respectively have been determined by different collective bargaining processes which (considered separately) do not discriminate on grounds of sex and do not operate so as to disadvantage women because of their sex? Question 3: If the employer is able to establish that at times there are serious shortages of suitable candidates for job B and that he pays the higher remuneration to holders of job B so as to attract them to job B but it can also be established that only part of the difference in pay between job B and job A is due to the need to attract suitable candidates to job B? (a) is the whole of the difference of pay objectively justified or (b) is that part but only that part of the difference which is due to the need to attract suitable candidates to job B objectively justified or (c) must the employer equalize the pay of jobs A and B on the ground that he has failed to show that the whole of the difference is objectively justified?’

3. The parties have submitted their observations on those questions, as described in the Report for the Hearing ( 1 ).Details of the facts, as set out in the written observations of the parties, and the positions adopted by the parties will be reproduced hereinafter only in so far as is necessary for the purposes of the argument.

B — Analysis

Preliminary observations

4. The Court of Appeal has not based the reference expressly either on a case of direct or a case of indirect sex discrimination. The parties' arguments appear to fall within the legal framework of indirect discrimination. According to the Court of Appeal's statement of the relevant facts, the tribunal of fact considered that neither intentional or unintentional direct discrimination nor intentional or unintentional indirect discrimination had been proved. It cannot be established with certainty whether the appeal to the Court of Appeal by the plaintiff in the main proceedings has resulted in the subjectmatter of the proceedings being actually restricted to particular forms of discrimination. The appraisal of the case must be based on the statement of the facts of the court making the reference which is authoritative for the purposes of the Court of Justice.

The assumption that the jobs are of equal value

5. The Court must also proceed on the Court of Appeal's premiss that job A and job B arc to be considered to be of equal value for the purposes of the proceedings. The existence of the same work or work to which equal value is attributed within the meaning of Article 1 of Directive 75/117 ( 2 ) which to that extent facilitates the practical application of the principle of equal pay laid down in Article 119 of the EEC Treaty ( 3 ) is fundamental to a claim that there has been sex discrimination with regard to pay.

6. The reservations of the German Government regarding the assumption that the jobs being compared are of equal value are indeed probably due to the fact that a major part of the burden of making out a case and the burden of proof which are incumbent on a plaintiff alleging pay discrimination relates to the work being the same or of equal value.

7. The fact that the Court of Appeal, like the lower courts hearing the case, assumed the equal value of the jobs to be compared is a result of the possibilities afforded by the procedural rules in the legal system of the Member State concerned. Examination whether two jobs are of equal value may sometimes entail an extensive and costly study. Under national procedural law the hearing of evidence can be postponed pending the consideration of points of law.

The comparability of the jobs

8. It was stated in the course of these proceedings that under the law of the Member State concerned it is in principle possible to have a report made on whether different jobs performed in the same undertaking or in any case for the same employer arc of equal value. Only if the jobs are manifestly not comparable may the court decline to have their comparability examined.

9. The German Government's reservations that only comparable circumstances can and may be compared ought to be taken into account, first, when the admissibility of the comparative study is considered and, secondly, when the comparability is examined.

10. In the circumstances of the present case, it cannot be assumed that the jobs are manifestly incomparable. The main proceedings are concerned not with an abstract comparison between the jobs of members of two professional groups, namely speech therapists on the one hand and pharmacists on the other, but with a comparison between particular jobs specified by reference to actual named persons who are performing those jobs. Apart from the criterion of the profession of which they form part, the jobs being compared are also classified by reference to further material characteristics, such as their position within the hierarchy, management function, responsibility etc., the comparison being one expressly relating to particular managerial posts. Comparisons of that type are moreover customary for grading purposes in the public service, whether for civil servants or military personnel.

11. Under these circumstances, the factual premisses cannot be regarded as improper. There is certainly no indication of an overhasty approach to the constituent elements of pay discrimination, which must be carefully examined.

12. Moreover, since consideration of the relevance to the case pending before it of the question for a preliminary ruling lies in principle within the discretion of the court making the reference ( 4 ) and there are no indications of that power being misused, ( 5 ) the Court of Justice cannot depart from the premisses set out by the national court in its order for reference, which circumscribe the factual and legal context of the questions to be answered by the Court of Justice. ( 6 )

The first question ( 7 )

— Preliminary comments

13. The first question in the order for reference is concerned with the apportionment of the burden of proof in a case of alleged pay discrimination. The extent of the burden of making out a case and the burden of proof which are incumbent on the parties in a dispute concerning sex-related pay discrimination can differ according to whether the case is one of direct or indirect discrimination. I refer to my Opinion in Case 109/88 ( 8 ) with regard to the basic criteria for distinguishing between those two forms of sex discrimination and the associated requirements as to making out a case and the burden of proof in the proceedings.

14. From the description of the facts in the main proceedings it is not clear whether those proceedings concern a case of indirect or direct discrimination. The basic legal position is that Article 119 of the EEC Treaty and the directives adopted for its implementation, ( 9 ) as interpreted and applied by the Court of Justice, prohibit all forms of sex-related discrimination. ( 10 ) Sex-related pay discrimination takes various forms, the categorization of which can pose a legal problem. In order to render them susceptible to legal categorization, the courts have adopted the categories of direct and indirect discrimination. The conceptual scheme applied should in no way be construed in the sense of any exclusiveness of possible forms of sex discrimination. A glance at the conceptual scheme applied in these proceedings under the laws of the United Kingdom bears this out. The reference there to intentional or unintentional direct discrimination and to intentional or unintentional indirect discrimination shows that there arc four possible ways of categorizing the same phenomenon for legal purposes.

15. The purpose of a conceptual scheme is to comprehend methods by which women are placed at a disadvantage in their working lives and not to create additional obstacles to claims being made before the courts in respect of sex-related pay discrimination. For this reason, a formalistic approach should not be adopted when categorizing actual instances where women are placed at a disadvantage at work. In accordance with the result-orientated line taken by the Court of Justice in the past, a pragmatic approach ought to be pursued. ( 11 )

16. For example, in its judgment in Case 109/88 Danfoss the Court did not expressly base itself on any of the sex discrimination concepts set out in its previous case-law but gave an answer couched in general terms to the question posed in that case regarding the burden of proof, although there was there certainly cause for doubt as to whether it was direct or indirect sex discrimination that was in issue.

17. The present case is a good illustration of the difficulties caused by the classification of an actual phenomenon within one of the concepts, whilst in the result a woman can be clearly seen to be paid less than a man doing work of equal value for the same employer.

18. Nevertheless, in the following examination I will take as my starting point the conceptual scheme hitherto adopted by the Court. — The burden of proof in cases of direct discrimination

19. In cases of direct discrimination it is necessary and sufficient to carry out an actual comparison of the pay received by a female employee and that received by a male employee performing for the same employer work which is the same or of equal value. During the course of the proceedings the plaintiff must put forward a male comparator from the same undertaking who is doing work which is the same or of equal value and who is being paid more. ( 12 )

20. Since in the case of direct discrimination sex is, by definition, the cause of the less favourable pay or treatment, there must also exist a causal connection between the sex of the worker and the lower pay.

21. It is questionable whether the plaintiff bears the full burden of proof for establishing that causal connection. As the categorization into unconscious/unintentional direct discrimination shows, forms of direct sex discrimination are quite conceivable without sex being expressly mentioned in the contract of employment, pay scales or collective agreement as the criterion for the higher or lower pay. The conceptual scheme of that category makes it clear that discrimination does not even have to have been intentional.

22. The allocation of particular wage or salary scales to particular jobs can result in direct discrimination. Reference may here be made simply to the classic example of a physically demanding job which requires the use of considerable effort in comparison with a job which requires a high degree of manual dexterity. ( 13 )Direct sex discrimination can be caused by the adoption of distinguishing criteria of that kind for the purposes of pay. In order to prevent that, the test of work of equal value was expressly adopted as a constituent factor under Article 1 of Directive 75/117. ( 14 ) That is why the Commission, when monitoring the implementation of the directive into national law, attached great importance to the inclusion in the legislation of the Member States of the criterion of work of equal value, and it received the full support of the Court of Justice in so doing. ( 15 )

23. Since that form of direct pay discrimination is not expressly based on the sex of the worker, a female worker claiming equal pay encounters evidential difficulties if she has to prove the causal connection between her sex and the lower pay.

24. Nor can the onus of proof be discharged by showing there were no other reasons for the unequal treatment. That would amount to proving a negative which in principle cannot be required. For those reasons, when all the objective elements of discriminatory pay (work that is the same or of equal value, lower pay for a woman when compared with a man in the same undertaking) have been proved, there should be a rebuttable presumption of sex discrimination.

25. As stated above, ( 16 ) therefore, it is sufficient for the plaintiff to prove an example of the same (or equivalent) work by a man being better paid than that by a woman. It is then for the employer to furnish counterevidence, for example by adducing objective grounds for the unequal pay which are not based on the sex of the recipient.

26. It may be concluded at this stage, therefore, that in cases of direct discrimination, the employer must objectively justify differences in pay.

Indirect discrimination

27. The concept of indirect discrimination is a legal concept which enables cases of unequal treatment, for which there is an objective justification but which in fact result in the woman being disadvantaged, to be included as an instance of unlawful sex discrimination.

28. The contention that amongst the factual ingredients of indirect discrimination there must be a requirement or a hurdle ( 17 ) which is more difficult for women to meet or to overcome and therefore results in women being disadvantaged, is only partly applicable to the nature of indirect discrimination. The fact that the application of an objective criterion results in women being disadvantaged means that, for the disadvantage to be remedied, the very use of the objective criterion must be classified as part of the unlawful conduct. In cases in which it is established that a group of women is being disadvantaged in comparison with a group of male workers (doing work which is the same or of equal value in the same plant or undertaking) no additional factor, whereby unequal treatment is applied, need be required.

29. In the cases concerning indirect discrimination hitherto brought before the Court ( 18 ) the disadvantaging of female workers was effected by reference to an objective criterion.

30. The resultant disadvantage arose from the fact that women were affected by the criterion more than men. The Court has accepted as the cause of that effect reasons linked to the social role of women. For example, when the Court considers indirect discrimination against women to be possible in reference to the characteristic of part-time employment ‘taking into account the difficulties encountered by women workers in working fulltime’, ( 19 ) it is thereby recognizing that, as a result of their role in the family and in the bringing-up of children, women regularly meet considerable difficulties in working fulltime. If under those circumstances women have to rely on part-time employment, then the link to part-time employment affects women specifically.

31. At first sight a link to an objective criterion through which the discrimination is caused cannot be identified from the facts underlying the reference for a preliminary ruling. The case to be decided is, however, characterized by the particularity that the professional group to which the plaintiff belongs is a ‘purely female profession’. If 98% of all persons engaged in that profession are women, then rules that are linked to membership of the professional group can be rules specifically relating to women.

32. The plaintiff's representative is correct in stating that in the case of a purely female profession the link to membership of that profession can have effects which are similar to a link with part-time work. According to the information before the Court, the fact that speech therapists are almost exclusively women is also at least partly due to the connection between the social role of women and work. The opportunities of working part-time and of flexible arrangement of working hours are particularly attractive to women.

33. A collective agreement, which in those circumstances includes rules applying exclusively to that professional group, may also represent rules specifically relating to women.

34. If, on a purely formal view, in the course of the examination of a case of indirect discrimination, the existence of a reference criterion affecting women as a group in a particular way is required, in the case of a ‘purely female profession’ that can be both the link to the membership of the profession and also to the collective agreement relating to that profession.

35. As I have already stated in my basic comments regarding the nature of indirect discrimination, attention should be directed less to the existence of a requirement or a hurdle by means of which women suffer a disadvantage, and more to the discriminatory result. ( 20 ) Against that background, it is part of the nature of indirect discrimination that a comparison between the sexual groups ( 21 ) is carried out in order to determine the alleged discriminatory effect. With regard to the allocation of the burdens in the proceedings, that signifies that an actual comparison between two jobs is not sufficient. What is called for is a comparison between representative groups of employees, each doing work of equal value.

36. In the case of the main proceedings that would require a comparison between particular managerial posts and that has in fact evidently been commissioned. If it reveals that the group consisting principally of women suffered a significant disadvantage when compared with the male group comparator, a presumption of indirect sex discrimination will thus arise.

37. According to the Court's case-law, ( 22 ) the employer, in order to avoid the charge of sex discrimination, would have to show that the measures that have led to that result were ‘based on objectively justified factors unrelated to any discrimination on grounds of sex’ ( 23 ) or could ‘be explained by factors which exclude any discrimination on grounds of sex’. ( 24 )

38. In a context of indirect discrimination the plaintiff can therefore also, by proving objective facts, raise a rebuttable presumption of sex discrimination.

39. The structure of the reasoning for both direct discrimination and indirect discrimination is comparable with regard to the evidentiary aspect of the proceedings inasmuch as a rebuttable presumption of discrimination can be raised, in one case by means of a specific comparison and, in the other, by a comparison of groups, which places the onus on the employer to adduce evidence in rebuttal of that presumption or to produce a justification.

40. The answer to the first question in the order for reference must therefore be that the principle of equal pay enshrined in Article 119 of the EEC Treaty requires the employer to justify objectively the difference in pay between job A and job B.

The second question

41. The Court of Appeal's second question is concerned with how such a difference can be justified. The Court of Appeal would like to know whether the difference in pay can be sufficiently justified by the fact that ‘the pay of jobs A and B respectively have been determined by different collective bargaining processes being processes which (considered separately) do not discriminate on grounds of sex and do not operate so as to disadvantage women because of their sex’.

42. The starting point must be that the principle of equal pay under Article 119 of the EEC Treaty, as embodied in Article 1 of Directive 75/117, is a superior principle of law which the parties to a collective agreement cannot choose to disregard. The principle of equal pay is not only binding on the legislature ( 25 ) but has been held by the Court to be directly applicable. ( 26 ) Consequently the principle has effects in the relations between employer and employee. ( 27 ) Collective agreements must also stand up to scrutiny under Article 119 of the EEC Treaty. ( 28 ) The fact that the parties to the collective agreement are acting independently does not remove the need for them to observe the principle of equal pay.

43. The Court of Appeal's question asks in effect whether the fact that the jobs being compared fall within the scope of different collective agreements is of itself a sufficient justification for the sex-related difference in salary which has been found to exist.

44. At the hearing the United Kingdom referred to what I said in my Opinion in Case 109/88. ( 29 ) I there took the view that in the case of collective agreements negotiated and concluded for branches of trade or industry, membership of the particular branch could serve as the objective distinguishing criterion for the difference in pay.

45. The representative of the German Government referred at the hearing to the collective agreements between associations {Verbandstarifverträge) which are common in Germany and contended that a comparison between two jobs which fall within the scope of different collective agreements is not permissible.

46. As I have already stated in my Opinion in Case 109/88, I believe that in that type of collective agreement the very factor of work which is the same or of equal value may be lacking. Moreover, objective justification for any differences in pay may be deduced from the conduct of the negotiations for the collective agreement and from the collective agreement itself.

47. The justification cannot however be so extensive that a difference in pay which has arisen within the scope of two collective agreements would be altogether excluded from review. That applies in particular in the case of collective agreements within the same firm where one element in the principle of equal pay is present in so far as the employer is the same.

48. The particular facts of the main proceedings clearly reveal how, by means of a collective agreement concluded for only one professional group, a special rule can be adopted which, in the present case, can even take effect as a rule relating specifically to women. Inasmuch as the collective agreement itself is apt to produce inequality of treatment, it cannot at the same time serve as a justification for that same inequality of treatment. In those circumstances the fact that the collective agreement exists does not render further examination unnecessary.

49. Nor does the finding that the negotiations for each of the collective agreements were carried out in a non-discriminatory manner and the negotiated collective agreements are arranged in a nondiscriminatory way suffice in itself to justify a difference in pay for work of equal value for the same employer. Since justification of the discriminatory result is called for, ( 30 ) it cannot be sufficient to explain the causes leading to the discrimination. In particular, references to historical and social reasons cannot, in a case such as the main proceedings, be recognized as factors ‘which are objectively justified and unconnected with discrimination on the grounds of sex’. ( 31 ) The historical and social context of a ‘purely female profession’ is most probably sex-related. If an explanatory approach were accepted as sufficient justification, that would lead to the perpetuation of sexual roles in working life. Instead of the equality of treatment which is sought, there would be afforded a legal argument for maintaining the status quo.

50. The second question must therefore be answered as follows: it is not sufficient justification for the difference in pay for the common employer to refer to the existence of different collective agreements even if, considered separately, neither discriminates on grounds of sex.

The third question

51. Finally, with its third question the Court of Appeal seeks to find out what other reasons can be adduced to justify objectively the difference in pay and the extent to which they apply.

52. First of all, it cannot be disputed that an employer may be compelled by the state of the labour market to offer higher remuneration for members of a particular professional group in order to attract suitable applicants. Inasmuch as the need for that enhanced rate of pay is justified, it must also be taken into account when comparing pay for jobs A and B within the meaning of the order for reference. The only question then is the extent to which the objective reason can serve to justify the difference in pay.

53. If a pro rata justification is to be permitted, the effect of the objective criterion on the level of pay must be quantifiable. The Employment Appeal Tribunal, the United Kingdom and the defendant were all of the opinion that a series of factors go to determine the level of pay and it is not possible to ascribe a particular amount to any one of those factors. But elsewhere it is asserted that the requirements of the labour market justify a difference in pay of at most 10%. ( 32 ) On that basis it would appear to be quantifiable. The very fact that several factors influence the level of pay ought to make it possible to ascribe part of the pay to each of those factors.

54. The only appropriate solution to the problem is, in my opinion, to recognize that the difference in pay is justified in part. An unlimited obligation on the employer to equalize pay despite partial justification of the difference in pay (option (c)) would disregard the objective justification which has been alleged and ought to be accepted. Blanket justification of any difference in pay (option (a)) would however go far beyond the justification which is permissible and recognized. Inasmuch as it must be assumed that several factors influence the level of pay offered, blanket justification would also cover other reasons which would mean abandoning to that extent an examination of the objective justification which may well be supplied by other factors.

55. If one factor, which is not the cause of the whole of the difference in pay, were allowed to justify the whole difference, that would again leave open the door to potential discrimination.

56. In so far as the Commission's observations reveal any reservations that a pro rata justification would lead to a hypothetical comparison which the Court of Justice has not permitted in another context, ( 33 ) I am unable to share such doubts.

57. Although the Court did not permit a plaintiff in a case concerning equal treatment to compare pay or conditions of employment with a hypothetical comparator, ( 34 ) that is a substantively different situation from the position where the employer, on the basis of the comparison undertaken and the evidence adduced therefor, is obliged to provide evidence in rebuttal or to justify his pay policy and, accordingly the extent of an actual, existing justificatory factor falls to be assessed.

58. A court called on to assess the objective justification should seek to quantify the relevant factors. Where there are any difficulties in establishing the respective figures, the court must use its discretion to carry out an apportionment in accordance with the rules on the free evaluation of evidence.

59. The third question must therefore be answered as follows: if the employer is able to establish that at a given time there is a considerable shortage of suitable candidates for job B and that he pays the higher remuneration to holders of job B so as to attract them to job B but it can also be established that only part of the difference in pay between job B and job A is attributable to the need to attract suitable candidates to job B, only that part of the difference which is attributable to the need to attract suitable candidates to job B is objectively justified.

C — Conclusion

60. In summary I propose that the questions referred for a preliminary ruling be answered as follows: (1) The principle of equal pay enshrined in Article 119 of the Treaty of Rome requires the employer to justify objectively the difference in pay between job A and job B. (2) It is not sufficient justification for the difference in pay for the common employer to refer to the existence of different collective agreements even if, considered separately, neither discriminates on grounds of sex. (3) If the employer is able to establish that at a given time there is a considerable shortage of suitable candidates for job B and that he pays the higher remuneration to holders of job B so as to attract them to job B but it can also be established that only part of the difference in pay between job B and job A is attributable to the need to attract suitable candidates to job B, only that part of the difference which is attributable to the need to attract suitable candidates to job B is objectively justified.

( *1 ) Original language: German

( 1 ) Sec the Report for the Hearing at p. I-5540 et seq.

( 2 ) Council Directive 75/117/EEC of 10 February 1975 on the approximation of the laws of the Member Stales relating to the application of the principle of equal pav for men and women (OJ 1975 1. 45, p. 19).

( 3 ) Case 96/80 Jenkim v Kingsgate [1981] ECR 911. at para graph 22.

( 4 ) Case 83/78 Pigs Marketing Board [1978] ECR 2347; Case 283/81 Cilfit [1982] ECR 3415.

( 5 ) Case 231/89 Gmitrzynska-Bseber [1990] ECR I-4003, at paragraph 15 et seq.

( 6 ) Judgment of 26 January 1993 in Joined Cases C-320/90, C-321/90 and C-322/90 Telemarsicabruzzo [1993] ECR I-393, at paragraph 6.

( 7 ) See the Report for the Hearing, p. 4.

( 8 ) Opinion in Case 109/88 Handels- og Kontorfunkdonaeremes Forbund i Danmark v Dansk Arbejdsgiverforening, acting on behalf of Danfoss [1989] ECR3209, point 25 et seq.

( 9 ) See in particular Article I of Directive 75/117 and Article 2 of Council Directive 76/207 of 9 February 1976 on the implementation of the principle of equal treatment for men and women as regards access to employment, vocational training and promotion, and working conditions (OJ 1976 L 39, p. 40).

( 10 ) In the Court's earlier case-law it was at least doubtful whether both direct and indirect discrimination fell directly within the scope of Article 119 of the EEC Treaty- See the judgment in Case 43/75 Defrenne [1976] ECR 455, at para graph 23, and Case 129/75 Macarthys [1980] ECR 1275, at paragraph 15. Since the judgments in Case 69/80 Wor ringhimi and Humphreys v Lloyds Bank [1981] ECR 767, at paragraph 23, and Case 96/80 Jenkins v Kingsgate [1981] ECR 911, at paragraph 17, the Court has regarded indirect discrimination as being expressly caught by Article 119 of the EEC Treaty.

( 11 ) On the obligation as to the result to be achieved laid down in Article 119 of the EEC Treaty, see the judgment in Case 43/75 De/renne, cited above; judgment in Case 171/88 Rinner Kuhn [1989] ECR 2743, at paragraph 9, and the case law on indirect discrimination in general: Case 96/80 Jen kins, cited above; Case 170/84 Buka v Weber von Hartz [1986] ECR 1607; Case C 33/89 Koualska [1990' ECR 1 2591; Case C 184/89 Nunz [1991] ECR I 297 and Case C 360/90 Botel [1992] ECR I 3591

( 12 ) In cases of direct discrimination on the basis of the criterion of sex the requirement for a male comparator to be adduced may even not apply. Sec judgment in Case C-177/88 Dekker [1990] ECR I-3941, at paragraph 17 et seq.

( 13 ) On the permissible distinctions in rates of pay and on a non-discriminatory arrangement of the pay-rate classification system, see the judgment in Case 237/85 Rummler v Dato-Druck [1986] ECR 2101, at paragraph 24 et seq.

( 14 ) Case 237/85 (Rummler, cited above, at paragraph 11 et seq.).

( 15 ) Case 61/86 Commission v United Kingdom [1982] ECR 2601 and Case 143/83 Commission v Denmark [1985] ECR 427.

( 16 ) See point 19 above.

( 17 ) This is the position adopted by the United Kingdom and the defendant in these proceedings.

( 18 ) Case 96/80 Jenkins, cited above; Case 170/84 Bilka, cited above; Case 171/88 Rinner-Kubn, cited above; Case C-33/89 Kowalska, cited above; Case C-184/89 Nimz, cited above, and Case C-360/90 Botel, cited above.

( 19 ) Case 170/84 Bilka, cited above, at paragraph 29; a substantivelv similar approach was set out in Case 96/80 Jenkins, cited above, at paragraph 13; see also judgment in Case 360/90 Bötel, cited above, at paragraph 18, with reference to the judgment in Case 171/88 Rinner-Kuhn, cited above.

( 20 ) On the obligation as to the result to be achieved, sec judgment in Case 43/75 Defrenne, cited above, and Case 171/88 Rinner-Kühn, cited above, at paragraph 9.

( 21 ) Case 171/88 Rinner-Kühn, cited above.

( 22 ) Case 96/80 Jenkins, cited above, at paragraph 13; Case 170/84 Bilka, cited above, at paragraph 31; Case 171/88 Rmner-Ktihn, cited above, at paragraph 12; Case C-33/89 Kowalska, cited above, at paragraph 13; Case C-184/89 Nimz, cited above, at paragraph 14, and Case C-360/90 Botel, cited above, at paragraph 21.

( 23 ) Case 170/84 Bilka, cited above.

( 24 ) Case 96/80 Jenkins, cited above, at paragraph 13; Case 170/84 Bilka, cited above, at paragraph 29.

( 25 ) Case 171/88 Rinner-Kuhn, cited above; Case C-360/90 Sole/, cited above.

( 26 ) Case 43/75 Defrenne, cited above, at paragraph 39.

( 27 ) Case 43/75 Defrenne, cited above; Case C-33/89 Kowalska, cited above, at paragraph 12. Sec Article 4 of Directive 75/117; see also Article 5 of Directive 76/207 on the implementation of the principle of equal treatment for men and women as regards access to employment, vocational training and promotion, and working conditions (OJ 1976 L 39, p. 40).

( 28 ) Case 143/83 Commission v Denmark, cited above, on the relevant provisions of Directive 75/117; Case 165/82 Commission v United Kingdom [1983] ECR 3431, at paragraph 11, and Case 312/86 Commission v France [1988] ECR 6315, at paragraph 23, on the relevant provisions of Directive 76/207; Case 109/88 Danfoss, cited above; Case C-33/89 Kowalska, cited above, and Case C-184/89 Nimz, cited above.

( 29 ) Opinion in Case 109/89 Danfoss, cited above, at point 46.

( 30 ) Case 43/75 Defrenne, cited above; Case 171/88 Rinner-Kühn, cited above.

( 31 ) Case 170/84 Bilka, cited above, at paragraph 31.

( 32 ) The plaintiffs contention; also reproduced in the judgment of the Court of Appeal preceding the reference for a preliminary ruling (Annex 2 to the plaintiffs written observations, at p. 32).

( 33 ) Case 129/79 Macarthys, cited above, at paragraph 15.

( 34 ) Case 129/79 Macarthys, cited above.