CELEX: 62006CC0231
Language: en
Date: 2007-03-29
Title: Opinion of Advocate General Kokott delivered on 29 March 2007. # Office national des pensions v Emilienne Jonkman (C-231/06) and Hélène Vercheval (C-232/06) and Noëlle Permesaen v Office national des pensions (C-233/06). # Reference for a preliminary ruling: Cour du travail de Bruxelles - Belgium. # Equal treatment for men and women - Statutory pension scheme -Directive 79/7/EEC - Air hostesses - Grant of a pension equal to that of stewards - Payment of adjustment contributions in a single payment - Interest payments - Principle of effectiveness - Obligations on a Member State as a result of a preliminary ruling. # Joined cases C-231/06 to C-233/06.

OPINION OF ADVOCATE GENERAL
      Kokott
      delivered on 29 March 2007 (1)
      
      Joined Cases C‑231/06 to C‑233/06
      Émilienne Jonkman and Others
      (References for a preliminary ruling from the Cour du travail, Brussels (Belgium))
      (Social policy – Social security for employed persons – Equal treatment of men and women– Statutory pension scheme – Special scheme for air crew – Procedure for adjustment – Arrangements for retroactive insurance of a category of persons originally excluded – Gender discrimination – Principle of effectiveness)I –  Introduction
      1.     The object of the present references for a preliminary ruling is yet again the legal status of Belgian air hostesses in comparison
         with their male colleagues, a subject which was brought before the Court as early as the 1970s and led to its three Defrenne (2) judgments. The case-law having since then considered in particular the principle of equal pay for men and women and their
         equal treatment in terms of conditions of employment in a number of cases, this case returns to the starting theme of the
         Defrenne case-law, namely the issue of equal treatment of men and women as regards statutory pension schemes.
      
      2.     From 1964 to 1980, the statutory pension scheme in Belgium included a special scheme for male cabin crew, allowing them to
         obtain a higher pension than was otherwise available under the scheme which applied generally to employees. However, for that
         purpose they had to pay higher pension contributions.
      
      3.     This special scheme has been available to female cabin crew only since 1981. (3) For periods during which they made contributions before 1981, female cabin crew could obtain the benefit of the special scheme
         retroactively only if they made retroactive contributions. For this purpose an ‘adjustment procedure’ was created in 1997,
         which required the persons concerned to pay adjustment contributions in the form of a single global payment, plus 10% interest
         per annum from the end of the relevant contribution year.
      
      4.     The present proceedings seek to have this adjustment procedure, which enables equal treatment for the persons concerned only
         at significant financial cost, considered by reference to Community law. The question is whether the arrangements for retroactive
         contributions as now provided for in Belgian law for former air hostesses do not deprive the principle of equal treatment
         of men and women of practical effect.
      
      II –  Legal framework
      A –    Community law
      5.     Council Directive 79/7/EEC (4) aims at the progressive implementation of the principle of equal treatment for men and women in matters of social security.
         Article 3(1)(a) provides that the directive applies inter alia to statutory schemes which provide protection against the risk
         of old age.
      
      6.     Article 4(1) of Directive 79/7 provides as follows:
      ‘The principle of equal treatment means that there shall be no discrimination whatsoever on ground of sex either directly,
         or indirectly by reference in particular to marital or family status, in particular as concerns:
      
      –       the scope of the schemes and the conditions of access thereto,
      –       the obligation to contribute and the calculation of contributions,
      –       the calculation of benefits including increases due in respect of a spouse and for dependants and the conditions governing
         the duration and retention of entitlement to benefits.’
      
      7.     The transposition period for Directive 79/7 expired on 23 December 1984. (5)
      
      B –    National law
      8.     With effect from 1 January 1964, a special scheme for ‘civil aviation air crew’ was introduced into the statutory pension
         scheme, which derogated from the general retirement and survivors’ pension scheme for employees. After re-enactment of the
         relevant provisions in 1969, the Royal Decree of 3 November 1969 (6) is the relevant legal basis for this special scheme.
      
      9.     The essential feature of the special scheme is that for air crew a larger part of their salary is taken into account both
         as regards levying of pension contributions and as regards calculating pension payments than in the general scheme for employees.
         Thus, those favoured by the special scheme could enjoy a higher pension than members of the general scheme for employees,
         although to do so they had also to pay higher pension contributions than the rules of the general scheme required.
      
      10.   Female air crew were originally expressly excluded from the special scheme, (7) with the effect that they had correspondingly lower pension entitlements. (8) It was not until a Royal Decree of 27 June 1980 (9) that, with effect from 1 January 1981, the advantages of the special scheme were extended to air hostesses, albeit not retroactively.
         Accordingly, as regards contribution periods between 1 January 1964 and 31 December 1980 the amounts of contributions and
         of pensions for air hostesses continued to depend on the general scheme for employed persons.
      
      11.   A Royal Decree of 25 June 1997 (10) was intended finally to ensure equal treatment of male and female air crew in respect of the period referred to of 1 January
         1964 to 31 December 1980. For this purpose an ‘adjustment procedure’ was inserted into the Royal Decree of 3 November 1969,
         which allowed affected air hostesses to benefit from pensions calculated on the same basis as those of male air crew, by means
         of retroactive contributions. These retroactive contributions are to be made by means of adjustment contributions by the persons
         concerned in the form of a single global payment for their periods of service between 1 January 1964 and 31 December 1980,
         plus 10% interest per annum from the end of the relevant contribution year.
      
      12.   The details of this adjustment procedure are laid down by the new Article 16b of the Royal Decree of 3 November 1969, (11) paragraphs 2 and 4(3) of which provide as follows:
      
      ‘…
      § 2.      Entitlement under the provisions of paragraph 1 (adjustment) is subject to payment in full of the employer’s and the employee’s
         pension contributions due under the special scheme for civil aviation air crew, after deduction of the amount of the employer’s
         and employee’s pension contributions paid as an employed person.
      
      …
      § 4.  … Simple interest, calculated at the rate of 10% per annum, is due for the period beginning at the end of each calendar year
         of the period subject to adjustment and ending on the date of the application for adjustment.
      
      …’
      13.   In addition, letter (b) of Paragraph 9(2) of Article 16b of the Royal Decree of 3 November 1969 provides that the recalculation
         of pension payments pursuant to the adjustment procedure shall take effect only when an application to make retroactive contributions
         is made, and only in respect of the future.
      
      III –  Facts and main proceedings
      14.   The subject of the main proceedings is disputes between three former air hostesses who used to work for the Belgian airline
         Sabena (12) and the Belgian Office national des pensions (‘ONP’) (13) concerning the calculation of their pensions. In essence, the three claimants in the main proceedings want their pensions
         to be calculated according to the special scheme for civil aviation air crew, which is to their advantage, without having
         to make retroactive contributions at a high financial cost for the period before 1 January 1981. However, the ONP rejects
         this claim.
      
      15.   In Case C‑231/06, by decision of 24 March 1997, the ONP granted to Ms Émilienne Jonkman, born on 24 February 1938, a retirement
         pension at the rate for single persons of an annual amount of BEF 536 960 (EUR 13 311) from 1 February 1997. The pension was
         calculated on a career record of 27/34, that is to say on the basis of the years 1966 to 1992 during which Ms Jonkman worked
         as an air hostess.
      
      16.   In Case C‑232/06, by decision of 6 May 1996, the ONP granted to Ms Hélène Vercheval, born on 25 June 1941, a retirement pension
         at the rate for single persons of an annual amount of BEF 682 915 (EUR 16 929) from 1 July 1996. That pension was calculated
         on a career record of 33/34 on the basis of an accepted professional career from 1963 to 1995 inclusive as an air hostess.
      
      17.   Finally, in Case C‑233/06, by decision of 16 December 1996, confirmed on 22 September 1997, the ONP granted to Ms Noëlle Permesaen,
         born on 3 January 1942, a retirement pension at the rate for single persons of an annual amount of BEF 676 734 (EUR 16 776)
         from 1 February 1997. That pension was calculated on the basis of a career record of 31/34 on the basis of an accepted professional
         career from 1966 to 1994 inclusive as an air hostess.
      
      18.   Ms Jonkman, Ms Vercheval and Ms Permesaen each brought an action against these decisions at the Tribunal du travail, (14) Nivelles, and complained of continuing discrimination against air hostesses by comparison with male air crew in respect of
         pension calculations for years before 1981.
      
      19.   After two of the claimants, Ms Jonkman and Ms Vercheval, succeeded at first instance, the ONP appealed against the respective
         judgments of the Tribunal du travail, Nivelles. (15) In the third set of proceedings, by contrast, the claimant, Ms Permesaen, succeeded only in part; she appealed against the
         judgment of the Tribunal du travail, Nivelles. (16) Thus, all three main proceedings come to be before the Brussels Cour de travail (17) (‘the national court’) on appeal.
      
      IV –  Request for a preliminary ruling and proceedings before the Court
      20.   By judgments dated 10 May 2006, the Brussels Cour du travail referred the following questions in Cases C‑231/06, C‑232/06
         and C‑233/06 to the Court for a preliminary ruling:
      
      (1)      With regard to the adjustment contributions (18)
      
      Is Directive 79/7/EEC … to be interpreted as meaning that it authorises a Member State to adopt rules intended to allow a
         category of persons of a particular sex, originally discriminated against, to become eligible for the pension scheme applicable
         to the category of persons of the opposite sex by making retroactive payment (a single payment of a very large sum) of contributions,
         recovery of which would be time-barred under the legislation applicable in that State in the case of the latter category of
         persons?
      
      If so, is not Directive 79/7/EEC … to be interpreted as requiring a Member State to amend legislation contrary to that provision
         as soon as a judgment of the Court of Justice of the European Communities rules that there is a conflict of norms and, at
         the very least, within the applicable time-limit for recovery of the contributions which have become payable by virtue of
         the adoption of those rules?
      
      (2)      With regard to the interest for late payment (19)
      
      Is Directive 79/7/EEC … to be interpreted as meaning that it authorises a Member State to adopt rules intended to allow a
         category of persons of a particular sex, originally discriminated against, to become eligible for the pension scheme applicable
         to the category of persons of the opposite sex by making payment of a large amount of late payment interest, recovery of which
         would be time-barred under the legislation applicable in that State in the case of the latter category of persons?
      
      If so, is not Directive 79/7/EEC … to be interpreted as requiring a Member State to amend legislation contrary to that provision
         as soon as a judgment of the Court of Justice of the European Communities rules that there is a conflict of norms and, at
         the very least, within the applicable time-limit for recovery of late payment interest due as a result of the adoption of
         those rules?
      
      21.   By order dated 21 June 2006, the President of the Court of Justice joined Cases C‑231/06, C‑232/06 and C‑233/06 for the purposes
         of the written and oral procedure and for judgment.
      
      22.   In the proceedings before the Court, in addition to the parties to the three sets of main proceedings the Commission of the
         European Communities has made written and oral submissions, and the Italian Government took part in the written procedure.
      
      V –  Analysis
      A –    Preliminary remarks
      23.   In the present case there is no dispute that in Belgium between 1964 and 1980 air hostesses suffered direct discrimination
         on the ground of sex, because within the framework of the statutory pension scheme the advantages of the special scheme for
         civil aviation air crew were denied them.
      
      24.   All that is in dispute is whether the adjustment procedure introduced in 1997 which was intended to remove all discrimination is itself compatible with the principle of equal treatment
         of men and women in the field of social security, as expressed in Directive 79/7.
      
      25.   The adjustment procedure referred to is based on the principle of retroactive contributions. Women who wish to take advantage
         of the benefits conferred by the special scheme are required to pay, first, adjustment contributions in the form of a single
         global payment and, second, interest on such adjustment contributions of 10% from the end of the relevant calendar year in
         the adjustment period. Both can impose significant financial burdens on the persons concerned.
      
      26.   The national court has made these features of the adjustment procedure the subject of both the questions it has referred.
         In essence it asks whether the principle of equal treatment of men and women precludes a provision for retroactive contributions
         which involves significant financial burdens on the persons concerned.
      
      27.   In this connection the national court rightly refers to Directive 79/7. Admittedly, the time-limit for transposing this directive
         is long after the contribution periods in question in the present case of 1964 to 1980. (20) However, the fact that the directive does not contain any provisions to the contrary means that it is applicable to all future
         (as well as, of course, to all present) effects of factual situations arising under the previous law. (21) It follows that the principle of equal treatment of men and women under Directive 79/7 must be applied to grants of pensions
         when claimed today by the claimants in the three main proceedings under the special scheme for civil aviation air crew.
      
      B –    The two questions referred
      28.   Given that the answer to the references for a preliminary ruling depends on the same considerations both as regards the adjustment
         contributions and as regards interest on them, I propose to consider both questions together.
      
      1.      The adjustment payments and interest on them in light of the principle of equal treatment
      29.   Article 4(1) of Directive 79/7, on which individuals can rely directly, (22) provides that the principle of equal treatment of men and women in the area of social security includes a requirement that
         there shall be no discrimination whatsoever on ground of sex either directly or indirectly as regards the conditions of access
         to statutory pension schemes and the calculation of benefits thereunder.
      
      30.   This provision gives expression to the principles of equal treatment and of non-discrimination, which are general principles
         of Community law and which have been consistently held to require that similar situations are not treated differently and
         different situations are not treated in the same way, so far as such treatment is not objectively justified. (23)
      
      31.   If a pensions contribution scheme is designed originally such that it benefited only one sex, the principle of equal treatment
         requires that workers discriminated against be placed in the same situation as workers of the other sex. (24) In practice this means two things:
      
      32.   First, such a scheme must – until it is either discontinued or amended – be extended to persons of the other sex, in order
         to remove the discrimination against them. (25)
      
      33.   Second, persons of the sex discriminated against cannot demand to be treated better in financial terms than if the scheme
         in question had been open to them from its inception; therefore, in particular, they cannot avoid making retroactive pension
         contributions for the period in question if they wish to claim the benefits of the special scheme. (26)
      
      34.   Against this background, there can in principle be no complaint that an adjustment procedure such as the Belgian one confers
         the benefits of the pension scheme for civil aviation air crew on the air hostesses originally excluded only if they make
         retroactive contributions by means of retroactive payments.
      
      35.   If one now conferred the benefits of the special scheme on former air hostesses without requiring them to make contributions
         corresponding to those their male colleagues made, then this would ultimately lead to unjustified equal treatment of substantially
         different situations: both categories of person would receive pensions calculated by reference to the more favourable special
         scheme, but only male air crew would have paid for this benefit by means of correspondingly higher pension contributions.
         At that time their female colleagues paid only the smaller contributions required by the general pension scheme and therefore
         received a higher net income.
      
      36.   Thus, an unjustified advantage would arise in favour of former air hostesses if one now granted them a higher pension, calculated
         in accordance with the special scheme, without requiring them to make adjustment payments pursuant to retroactive contribution
         provisions. (27)
      
      37.   However, whether it is also legitimate to require the payment of interest on such adjustment payments, having regard to the principle of equal treatment, depends on the specific structure and purpose
         of the particular interest provision.
      
      38.   There could be no complaint if, in the context of retroactive contributions, interest were charged on the adjustment payments
         for the purpose of adjusting for purchasing power in order to take account of inflation since the relevant time. Indeed, it would even be an expression of the equal treatment
         of all members within the meaning of Article 4(1) of Directive 79/7 if adjustment payments by air hostesses corresponded to
         the pension scheme contributions their male colleagues made during a comparable career record not only nominally but also in real terms.
      
      39.   The imposition of interest for the purpose of adjusting for purchasing power is, however, permissible only to the extent that
         inflation is not already taken into account in calculating the amounts of the adjustment payments. If the adjustment payments
         themselves are calculated taking inflation into account, inflation cannot be taken into account a second time by means of
         interest. At the oral hearing before the Court the ONP’s representative was not able to say definitively whether the adjustment
         payments demanded from the former air hostesses pursuant to the 1997 adjustment regulations already contained an element of
         purchasing power adjustment.
      
      40.   The Member States must be given discretion in determining what interest may be required in order to adjust for purchasing
         power. A flat rate of interest which on average ensures an appropriate adjustment for inflation must also be regarded as permissible to that extent. Only an interest rate
         that went beyond what was necessary to adjust for purchasing power would be incompatible with the principle of equal treatment,
         if it meant that persons originally discriminated against were required to pay contributions that were higher than those payable
         by other members not only nominally but also in real terms.
      
      41.   Irrelevant, however, is the interest rate former air hostesses could have obtained if they had invested the amount by which
         their net salaries exceeded those of their male colleagues on the capital markets each month from 1964 to 1980, that is the
         amount by which the contributions their male colleagues made to the special scheme exceeded the pension contributions generally
         required at that time in Belgium. This is because air hostesses were under no obligation to build up an additional, private
         pension fund of their own, or to set aside savings in case subsequent retroactive contributions were required. It follows
         that one cannot criticise them today for not having built up corresponding private savings.
      
      42.   It would be likewise inappropriate to require former air hostesses to pay interest on account of delay. As the claimants in the main proceedings rightly submitted, in the material period of 1964 to 1980 the law then in force
         in Belgium did not even permit them to make pension contributions under the special scheme for civil aviation air crew. The
         fact that they are able to make these contributions only now, retroactively, is not caused by any failure on the part of the
         air hostesses but is the direct consequence of the national legal system at the time which discriminated against them.
      
      43.   The references for a preliminary ruling simply assume that in the present case the persons concerned are required to pay interest on account of delay. (28) It is for the national court to reconsider in detail whether interest of 10% per annum, as provided for by the 1997 adjustment
         provisions, is not at least in part intended to adjust for purchasing power in relation to inflation since contribution years
         1964 to 1980. However, if the latter is the case the interest charge is legitimate only to the extent that it does not exceed what is necessary to make a reasonable adjustment for purchasing power.
      
      44.   Thus, by way of interim conclusion it is to be held that:
      A national provision intended to allow a category of persons of a particular sex, originally discriminated against, to become
         eligible for the more favourable pension scheme applicable to the category of persons of the opposite sex is not rendered
         incompatible with Directive 79/7 solely by the fact that it requires the persons concerned in making retroactive contributions
      
      –       to make adjustment payments
      and
      –       to pay interest on such adjustment payments, to the extent that the interest is not interest for late payment and does not
         exceed what is necessary to make a reasonable adjustment for purchasing power.
      
      2.      The requirement for effective enforcement of the right to equal treatment
      45.   Even if, in principle, a requirement for retroactive contributions is unobjectionable in terms of equal treatment of men and
         women, there remains to be considered whether a provision such as the Belgian one, which involves serious financial burdens
         on the persons concerned, can have effect having regard to the principle of equal treatment as laid down by Directive 79/7.
      
      46.   The principle of effectiveness (29) requires that the relevant provisions of national law may not render the enforcement of the right of persons concerned to
         equal treatment practically impossible or excessively difficult. The discretion which Member States have in the field of social
         policy cannot result in the undermining of a fundamental principle of Community law, such as that of equal treatment. (30)
      
      47.   The three claimants in the main proceedings have submitted without contradiction that the adjustment contributions they would
         be required to pay retroactively in the form of a single global payment, including interest, would amount to more than EUR
         60 000, (31) interest alone, at more than EUR 40 000, constituting the lion’s share of this amount.
      
      48.   It is obvious that the requirement to make a single global payment of the order of this amount renders it practically impossible,
         or at least excessively difficult, for the persons concerned to make retroactive contributions and thus to claim the benefits
         of the special scheme for civil aviation air crew.
      
      49.   In this context, it is in particular to be recalled that the persons concerned are already retired and, according to the ONP’s
         pension decisions, their pensions are between EUR 13 311 and EUR 16 929 per annum, which corresponds to a monthly pension
         of less than EUR 1 500. Accordingly, the single global payment, which must be made in advance, would be many times the annual
         pensions of the persons concerned, and even the retroactive payment of interest-free adjustment contributions would be significantly more than one year’s pension, being a single payment of approximately EUR
         20 000.
      
      50.   It follows that in order to make retroactive contributions, the persons concerned would have to draw on their savings to a
         significant extent, and might even have to go into debt. It is obvious that from the point of view of the claimants, who are
         no longer earning, this would be economically irrational. In case of doubt, the persons concerned would tend not to make retroactive
         contributions, because the financial burdens involved in doing so would be disproportionate to the increase in pension that
         could be achieved, of around EUR 2 500 per annum (EUR 208 per month). (32)
      
      51.   Accordingly, the claimants rightly submit that an adjustment procedure such as the Belgian one is not compatible with the
         principle of effectiveness and in reality perpetuates the discrimination they suffered.
      
      52.   In order not to thwart the effective enforcement of the right to equal treatment, the persons concerned would have to be permitted
         to pay their adjustment contributions and any interest on them by monthly payments instead of by a single global payment. (33) The postponed payment of the remainder of the relevant amount would contribute decisively to making the economic burden tolerable
         for the persons concerned.
      
      53.   Such an instalment model would not in any way lead to unlawful better treatment of the former air hostesses by comparison
         with their male colleagues, (34) but would on the contrary contribute to making their respective contribution burdens comparable, as the principle of equal
         treatment requires. (35) In any event, male air crew were not required to pay their pension contributions all at once, which were instead required
         to be paid over a period of years, or even decades, in the form of monthly payments, which were in addition tax deductible. (36)
      
      54.   The amount of the monthly payments must always be calculated taking all the circumstances of the individual case into account.
         In that regard, an appropriate starting point is the fact that the adjustment payments and any interest on them should be
         paid in full in the period during which it is anticipated that the pension will be paid.
      
      55.   However, in order to satisfy the principle of effectiveness, the total monthly burden on the persons concerned must be limited
         so that their retroactive contributions can give them a material benefit despite the adjustment payments and any interest
         that must be paid. Accordingly, the instalments of adjustment payments including interest must not take up the whole of the
         increase in monthly pension which a former air hostess may expect from claiming under the special scheme. It would for example
         be reasonable to retain approximately half of the resulting increase in pension as an instalment payment and to pay out the
         other half to the pensioners. (37)
      
      56.   It is correct to point out that the application of such a scheme of limited instalment payments allows the persons concerned
         to receive an increase in pension before they have paid all the contributions actuarially required. Indeed, it is possible
         that the persons concerned do not pay all the necessary adjustment payments during the period their pension is paid. (38) There is no doubt that this can lead to a certain increase in the financial burden on the State pension scheme.
      
      57.   However, the Member State whose legislation is the real cause of this discrimination on the ground of sex, and the institution
         operating the statutory pension scheme, must also bear any financial burdens which accompany the effective enforcement of
         the principle of equal treatment. Purely budgetary considerations cannot justify discrimination on the ground of sex. (39) Nor can they be pleaded later, when the issue is how to eliminate the consequences of past discrimination effectively.
      
      58.   In any event, in the present case neither the Belgian Government (40) nor the ONP has submitted any evidence that granting former air hostesses the benefits of the special scheme for civil aviation
         air crew before full payment of all adjustment contributions plus any interest would create a serious risk to the financial
         stability of the State pension scheme. (41)
      
      59.   Apart from anything else, it appears that in adopting the adjustment regulations the Belgian legislature did not take the
         approach that retroactive contributions by former air hostesses had to be neutral in budgetary terms. The 1997 adjustment
         regulations provide that only employee contributions are to be levied retroactively for contribution periods from 1964 to 1980, whereas employers are expressly exempted from retroactive payment of the pension contributions imposed on them. (42)
      
      60.   Accordingly, by way of interim conclusion it is to be held that:
      A national provision intended to allow a category of persons of a particular sex, originally discriminated against, to become
         eligible for the more favourable pension scheme applicable to the category of persons of the opposite sex is incompatible
         with Directive 79/7 to the extent that it involves such high financial burdens for the persons concerned in the form of single
         global payments that it makes retroactive contributions practically impossible or excessively difficult for them. It may be
         that payment by instalments must be permitted, the amount of those instalments being calculated so that, despite the adjustment
         contributions and any interest, the retroactive contributions can confer a material benefit on the persons concerned.
      
      C –    Final remarks
      1.      Commencement of retroactive contributions
      61.   During the oral hearing before the Court, it was pointed out that the Belgian 1997 adjustment regulations provide that any
         retroactive contributions have effect only for the future, so that the persons concerned can expect an increase in pension only in respect of the period after their application to make retroactive contributions. (43)
      
      62.   In principle, the enactment of reasonable exclusion provisions is compatible with Community law provided that the principles
         of equivalence and of effectiveness are observed. Accordingly, the Court has held that the Member States may lay down time-limits
         for raising proceedings, provided those principles are observed. (44)
      
      63.   In the same way, it must be possible to confer an increase in pension required by Community law on persons originally discriminated
         against only with effect from the date of the application and only for the future. Of course, this presupposes that any correction
         of other errors in calculating pension entitlements takes effect under national law only for the future (principle of equivalence). (45)
      
      64.   However, in that regard it is to be observed that a pension increase which is conferred only for the future cannot require
         the same amount of adjustment payments as a pension increase paid to the persons concerned retroactively. The principle of
         equal treatment requires the adjustment payments to be reduced and in this way account to be taken actuarially of the fact
         that the persons concerned will receive a higher pension not from the time they attain retirement age, but only from the significantly
         later time when they apply to make retroactive contributions.
      
      65.   Accordingly, if the national court holds that retroactive insurance for the claimants in the three sets of main proceedings
         has effect only for the future but still requires a special application, their adjustment payments and any interest on them
         are to be reduced accordingly. By contrast, if the national court concludes that the claimants’ appeals in the three sets
         of main proceedings against their pension notices constitute by implication applications to make retroactive contributions,
         the higher pension is to be awarded to them retroactively. In the latter case, the ONP can set off the adjustment payments
         due and any interest thereon against the pension increases payable retrospectively for the period from the attainment of pensionable
         age.
      
      2.      Limitation as regards contributions and interest
      66.   In its request for a preliminary ruling, the national court points out in particular that the limitation period for actions
         against male air crew for payment of contributions and interest in respect of the disputed period of 1964 to 1980 has already
         expired.
      
      67.   However, this in itself is not sufficient to prevent female air crew from being required to pay adjustment payments and interest
         if they wish to claim benefits under the special scheme for civil aviation air crew by means of retroactive contributions.
      
      68.   In terms of limitation periods, contributions by male air crew in respect of the period from 1964 to 1980 are not comparable
         to adjustment payments that female air crew have to make if they apply to make retroactive contributions. The respective liabilities
         to pay contributions do not arise at the same time and accordingly the time-limits for raising an action need not expire at
         the same time. On the contrary, it is only natural that liabilities to pay contributions and interest which have arisen earlier
         are subject to limitation earlier than those which arise only at a later stage, in consequence of an application by the person
         concerned to make retroactive contributions.
      
      69.   If one were to regard any action for payment of the adjustment payments and interest due by the former air hostesses as being
         precluded by limitation from the very beginning, the principle of retroactive contributions would be devoid of substance,
         and female air crew would in fact be in a better position than male air crew. Such a result would be incompatible with the
         principle of equal treatment of men and women. As already mentioned, (46) the members of the category of persons so far discriminated against cannot relieve themselves of liability to make retroactive
         pension contributions in respect of the period in question by reference to the principle of equal treatment.
      
      70.   However, the same limitation periods must of course apply for adjustment payments (including, as the case may be, those to
         be paid by instalments) and interest payable by female air crew from the time the respective liability arises as apply to pension contributions and interest payable by male air crew in respect of contribution years 1964 to 1980.
      
      3.      Restriction of the temporal effects of the judgment
      71.   In some of the cases which have concerned equal treatment of men and women, the Court has restricted the temporal effects
         of its judgment by reference to the principle of legal certainty. (47)
      
      72.   However, according to consistent case-law such a restriction is possible only by way of exception, (48) and only where two conditions are fulfilled. (49) First, there must be a risk of serious economic repercussions owing in particular to the large number of legal relationships
         entered into in good faith on the basis of rules considered to be validly in force. Second, it must appear that both individuals
         and national authorities have been led into adopting practices which do not comply with Community legislation by reason of
         objective, significant uncertainty regarding the implications of Community provisions, to which the conduct of other Member
         States or the Commission may even have contributed.
      
      73.   In the present case, the first condition is in any event not fulfilled. As already stated, neither the Belgian Government
         nor the ONP has provided evidence that the solution put forward above gives rise to any fear of serious economic repercussions,
         such as the risk of a significant danger to the financial stability of the State pension scheme.
      
      74.   Accordingly, there is no reason for the Court to restrict the temporal effects of its judgment in the present case.
      VI –  Conclusion
      75.   In the light of the foregoing observations, I suggest to the Court that it should answer the Brussels Cour de travail as follows:
      (1)      A national provision intended to allow a category of persons of a particular sex, originally discriminated against, to become
         eligible for the more favourable pension scheme applicable to the category of persons of the opposite sex is not rendered
         incompatible with Directive 79/7 solely by the fact that it requires the persons concerned in making retroactive contributions
      
      –       to make adjustment payments
      and
      –       to pay interest on such adjustment payments, to the extent that the interest is not interest for late payment and does not
         exceed what is necessary to make a reasonable adjustment for purchasing power.
      
      (2)      However, such a provision is incompatible with Directive 79/7 to the extent that it involves such high financial burdens for
         the persons concerned in the form of single global payments that it makes retroactive contributions practically impossible
         or excessively difficult for them. It may be that payment by instalments must be permitted, the amount of those instalments
         being calculated so that, despite the adjustment payments and any interest, the retroactive contributions can confer a material
         benefit on the persons concerned.
      
      1 –	Original language: German.
      
      2 –	Case 80/70 Defrenne I [1971] ECR 445, Case 43/75 Defrenne II [1976] ECR 455, and Case 149/77 Defrenne III [1978] ECR 1365, distinguishing between remuneration and other terms of employment.
      
      3 –	This inequality of treatment was already the subject of the judgment in Defrenne I (cited above, footnote 2), paragraphs 3 and 4, although at that time in connection with the interpretation of Article 119
         of the EEC Treaty.
      
      4 –	Council Directive 79/7/EEC of 19 December 1978 on the progressive implementation of the principle of equal treatment for
         men and women in matters of social security (OJ 1979 L 6, p. 24; ‘Directive 79/7’).
      
      5 –	This follows from Article 8(1) of Directive 79/7: on that point, see also Case 71/85 Netherlands v Federatie Nederlandse Vakbeweging [1986] ECR 3855, paragraphs 15 and 23, and Case C‑154/92 van Cant [1993] ECR I‑3811, paragraph 17.
      
      6 –	Moniteur belge of 10 December 1969, p. 11903.
      
      7 –	See number 2 of Article 1(1) of the Royal Decree of 3 November 1969, in which the definition of air crew includes the express
         addition ‘with the exception of air hostesses’ (‘à l’exclusion des hôtesses de l’air’). This inequality of treatment was explained
         on the basis that because of the age limit of 40 years in force at that time, air hostesses could not complete a full career
         record in their profession, and that for that reason the special provisions ought not to be available to them.
      
      8 –	On this basis the claimants in the main proceedings have calculated – and this is not contradicted – that, for example,
         the pension of a male air crew member after a 34-year career record ending on 1 January 1991 would be approximately BEF 733 760
         per annum (approximately EUR 18 189), but for a female crew member would be only BEF 611 290 (approximately EUR 15 153).
      
      9 –	Moniteur belge of 23 August 1980, p. 9700.
      
      10 –	Moniteur belge of 31 July 1997, p. 19635. A Royal Decree that had been previously enacted on 28 March 1984 (Moniteur belge of 3 April 1984, p. 4100) was set aside by the Belgian Council of State by judgment number 28435 of 2 September 1987.
      
      11 –	This provision was inserted by Article 4 of the Royal Decree of 25 June 1997.
      
      12 –	Société anonyme belge d’exploitation de la navigation aérienne.
      
      13 –	The State pensionable age.
      
      14 –	Labour Court.
      
      15 –	Judgments of 17 November 1997 and of 9 January 1998 respectively.
      
      16 –	Judgment of 26 December 2003.
      
      17 –	Higher Labour Court.
      
      18 –      Article 16b(2) of the Royal Decree of 3 November 1969, as amended by Article 4 of the Royal Decree of 25 June 1997.
      
      19 –      Article 16b(4)(3) of the Royal Decree of 3 November 1969, as amended by Article 4 of the Royal Decree of 25 June 1997.
      
      20 –	Directive 79/7 required to be transposed by 23 December 1984: see above, point 7.
      
      21 –	This is the consistent case-law of the Court: see, by way of example, Case 96/77 Bauche and Delquignies [1978] ECR 383, paragraph 48; Case C‑162/00 Pokrzeptowicz-Meyer [2002] ECR I‑1049 paragraph 50; Case C‑519/03 Commission v Luxembourg [2005] ECR I‑3067, paragraph 49; Case C‑28/00 Kauer [2002] ECR I‑1343, paragraph 20; and Case C‑154/05 Kersbergen-Lap and Dams-Schipper [2006] ECR I‑6249, paragraph 42.
      
      22 –	Netherlands v Federatie Nederlandse Vakbeweging (cited above, footnote 5), paragraphs 21 and 23, and van Cant (cited above, footnote 5), paragraphs 17 and 18.
      
      23 –	It is enough to refer to Case C‑147/02 Alabaster [2004] ECR I‑3101, paragraph 45; Case 
         C‑210/03 Swedish Match [2004] ECR I‑11893, paragraph 70; Case C‑110/03 Belgium v Commission [2005] ECR I‑2801, paragraph 71; and Case C‑300/04 Eman and Sevinger [2006] ECR I‑8055, paragraph 57.
      
      24 –	Case C‑128/93 Fisscher [1994] ECR I‑4583, paragraph 35.
      
      25 –	See generally on the requirement to extend the benefits of a provision to the category of persons discriminated against
         Case C‑15/96 Schöning-Kougebetopoulou [1998] ECR I‑47, paragraph 35, Case C‑442/00 Rodriguez Caballero [2002] ECR I‑11915, paragraph 42, Case C‑187/00 Kutz-Bauer [2003] ECR I‑2741, paragraph 72, and Case C‑81/05 Cordero Alonso [2006] ECR 
         I‑7569, paragraph 45; on Directive 79/7, in particular, see Netherlands v Federatie Nederlandse Vakbeweging (cited above, footnote 5), paragraph 23, van Cant (cited above, footnote 5), paragraphs 19 to 22, and Case 102/88 Ruzius-Wilbrink [1989] ECR 4311, paragraph 20.
      
      26 –	Fisscher (cited above, footnote 24), paragraphs 36 and 37, and Case C‑435/93 Dietz [1996] ECR I‑5223, paragraph 34, and the Opinion of Advocate General Van Gerven in Case C‑57/93 Vroege [1994] ECR I‑4541, point 30. Notwithstanding that these cases concern occupational pension schemes and consider them by reference
         to Article 119 of the EEC Treaty (now Article 141 EC), the considerations referred to may be applied by analogy to the statutory
         pension scheme in the present case and to Directive 79/7 without difficulty. Both Article 141 EC and Article 4 of Directive
         79/7 are expressions of the general principles of equal treatment and non-discrimination.
      
      27 –	In terms of Community law, in this context it is immaterial that the pension notices were issued to the claimants in the
         three sets of main proceedings prior to the enactment of the Belgian adjustment provisions in 1997. Community law did not at any time confer on the persons concerned a right to make retroactive contributions without making adjustment payments.
      
      28 –	On this point, the wording of the 1997 adjustment provisions is not entirely clear: Article 16b(4)(3) of the Royal Decree
         of 3 November 1969, as amended by the Royal Decree of 25 June 1997, uses the expression ‘simple interest’ (in French, ‘intérêt
         simple’), which sounds neutral. However, as the Commission rightly emphasised at the oral hearing, the same interest is described
         in Paragraph 6 of the same provision as ‘interest for late payment’ (in French, ‘intérêt de retard’).
      
      29 –	On the principle of effectiveness generally, see by way of example Case C‑78/98 Preston [2000] ECR I‑3201, in particular at paragraph 31, and Case C‑212/04 Adeneler [2006] ECR I‑6057, paragraph 95.
      
      30 –	Case C‑167/97 Seymour-Smith and Perez [1999] ECR I‑623, paragraph 75, and Kutz-Bauer (cited above, footnote 25), paragraph 57; to the same effect, see Case C‑208/05 ITC [2007] ECR I‑0000, paragraph 40.
      
      31 –	The single payment to cover the whole of the period from 1 January 1964 to 31 December 1980, including interest, would
         be more than EUR 63 000 (see calculations made by the ONP as of 19 November 1997 in relation to two comparable cases, which
         were produced by the claimants).
      
      32 –	According to uncontradicted information provided by the claimants in the main proceedings.
      
      33 –	Obiter, it may be mentioned that such an instalment payment scheme already exists in terms of the 1997 adjustment provisions,
         albeit restricted to cases in which the persons concerned have not been paid any pension so far (Article 16b(6)(3) of the Royal Decree of 3 November 1969, as amended by the Royal Decree of 25 June 1997).
      
      34 –	Again, see above, points 31 and 34.
      
      35 –	In this connection it is again to be recalled that according to the principle of equal treatment, the workers discriminated
         against are to be placed in the same situation as workers of the other sex: Fisscher (cited above, footnote 24), paragraph 35.
      
      36 –	In the proceedings before the Court, it has not been made clear whether and, if so, to what extent retroactive contributions
         and interest levied within the framework of the adjustment procedure would be tax deductible. In any event, given the modest
         amount of the claimants’ pension income, any deduction for tax would be hardly likely to produce any material benefits.
      
      37 –	For example, if the application of the special scheme for civil aviation air crew to a former air hostess resulted in a
         monthly pension increase of EUR 200 by comparison with a pension calculated in accordance with the general scheme for employees,
         it would be appropriate to pay out to the person concerned approximately EUR 100 of that amount and to retain the remaining
         EUR 100 as an instalment of the adjustment payments.
      
      38 –	The obligation to make adjustment payments must cease at the latest on the death of the person concerned, in order that
         her successors are not burdened with the financial consequences of the discrimination suffered by the former air hostess.
      
      39 –	This is the consistent case-law of the Court: see, for example, Case C‑343/92 Roks and Others [1994] ECR I‑571, paragraphs 35 and 36; Case C‑226/98 Jørgensen 2000] ECR I‑2447, paragraph 39; Joined Cases C‑4/02 and C‑5/02 Schönheit and Becker [2003] ECR I‑12575, paragraph 85; and Kutz-Bauer (cited above, footnote 25), paragraphs 59 and 60.
      
      40 –	The Belgian Government did not even participate in the proceedings before the Court.
      
      41 –	As regards this potential ground of justification, see – in the related area of fundamental freedoms – in particular Case
         C‑158/96 Kohll [1998] ECR I‑1931, paragraph 41, and ITC (cited above, footnote 30), paragraph 43.
      
      42 –	Article 16b(2) and (3) of the Royal Decree of 3 November 1969, as amended by the Royal Decree of 25 June 1997.
      
      43 –	As even the ONP confirmed at the oral hearing, this follows from letter (b) of Article 16b(9)(2) of the Royal Decree of
         3 November 1969, as amended by the Royal Decree of 25 June 1997.
      
      44 –	See, for example, Case 33/76 Rewe [1976] ECR 1989, paragraph 5; Case C‑231/96 Edis [1998] ECR I‑4951, paragraphs 20 and 35; and Case C‑30/02 Recheio – Cash & Carry [2004] ECR 
         I‑6051, paragraph 18.
      
      45 –	For example, one might think of a new calculation of pension entitlement in order to take appropriate account of certain
         periods of education or training of the pensioner.
      
      46 –	See above, points 33 and 34.
      
      47 –	See, in particular, Defrenne II (cited above, footnote 2), paragraphs 69 to 75, in particular paragraph 74, and Case C‑262/88 Barber [1990] ECR I‑1889, paragraphs 40 to 45, in particular paragraph 44.
      
      48 –	Case C‑209/03 Bidar [2005] ECR I‑2119, paragraph 67; Case C‑423/04 Richards [2006] ECR 
         I‑3585, paragraph 40; and Case C‑292/04 Meilicke and Others [2007] ECR I‑0000, paragraph 35.
      
      49 –	Bidar (cited above, footnote 48), paragraph 69, and Richards (cited above, footnote 48) paragraph 42.