This request for a preliminary ruling concerns the interpretation of Article 46a of Regulation 1408/71 and of Article 4(3) TEU and Articles 45 TFEU to 48 TFEU. It has been made in proceedings between Mrs van den Booren and the Rijksdienst voor Pensioenen (RvP, Belgian National Pensions Office; hereafter ‘NPO’) concerning the application of the Belgian rules against overlapping of benefits at the time of determination of the amount of the Belgian survivor’s pension received by Mrs van den Booren.

Mrs van den Booren resides in the Netherlands. Her husband, Mr Bartels, who died, worked as an underground miner in Belgium. The Belgian NPO granted Mrs van den Booren a Belgian survivor’s pension and from the same date Mrs van den Booren also received a Netherlands old-age pension. At a certain moment,

Mrs van den Booren’s Netherlands old-age pension was increased with retroactive effect, due to a change in the Dutch legislation. After that, the NPO notified Mrs van den Booren that its decision had been revised, to the effect that, as a result of the increase in her Netherlands old-age pension, her Belgian survivor’s pension, was being reduced. The NPO also requested reimbursement by Mrs van den Booren of the benefits overpaid.

When confronted with Mrs. van den Booren’s appeal against this decision, the Labour Court of Antwerp appealed to the ECJ to ascertain whether the provisions of Regulation No 1408/71, and more specifically Article 46a thereof, must be interpreted as precluding the application of legislative rules of a Member State containing a provision under which a survivor’s pension received in that Member State is reduced as a result of the increase in an old-age pension received under the legislation of another Member State, and whether, in the event of a negative reply, the primary law of the European Union, and more specifically Article 4(3) TEU and Articles 45 TFEU to 48 TFEU, prevents the application of such legislative rules.

It follows from Article 12(2) of Regulation 1408/71 that provisions on reduction laid down in the legislation of a Member State may, unless that regulation provides otherwise, be invoked against persons who receive a benefit from that Member State if they can claim other social security benefits, even when those benefits are acquired under the legislation of another Member State. An exception to the principle laid down in Article 12(2) of Regulation 1408/71 is contained in Article 46b(1) of that regulation, which provides that, in the case of overlapping of benefits of the same kind, provisions on reduction laid down by the legislation of a Member State do not apply to benefits calculated in accordance with Article 46(2) of that regulation.

In so far as it transpires that the Belgian survivor’s pension received by Mrs van den Booren was calculated on the basis of the professional career of her late husband and that she receives the Netherlands old-age pension in her own right, those two benefits cannot be considered to be benefits of the same kind coming within the abovementioned exception. Consequently, Regulation 1408/71 does not prevent the application of a national rule against overlapping such as that referred to by the national court, provided that the limits imposed by Regulation No 1408/71 are observed.

In that regard, Regulation 1408/71 provides, in particular in Article 46a(3)(d), that, if a rule against overlapping is applicable under the legislation of only one Member State on account of the fact that the person concerned receives benefits of the same kind or of a different kind payable under the legislation of another Member State, the benefit payable under the legislation of the first Member State may be reduced only within the limit of the amount of the benefits payable under the legislation of the other Member State. Accordingly, pursuant to that rule, the Belgian survivor’s pension of the person concerned may be reduced only within the limit of the amount of the Netherlands old-age pension. In those circumstances, the conclusion on that point must be that Article 46a of Regulation No 1408/71 does not preclude the application of legislative rules of a Member State containing a provision under which a survivor’s pension received in that Member State is reduced as a result of the increase in an old-age pension received under the legislation of another Member State, provided, in particular, that the conditions set out in Article 46a(3)(d) are observed.

However, the Court added that the finding that a national measure may be consistent with a provision of a secondary law measure, in this case Regulation 1408/71, does not necessarily have the effect of removing that measure from the scope of the Treaty’s provisions. Accordingly, it is for the national court to assess the compatibility of the rules of national legislation at issue with the requirements of European Union law by determining whether the Belgian rule against overlapping, which admittedly applies without distinction to Belgian nationals and to nationals of other Member States, does not in fact lead, in respect of the person concerned, to an unfavourable situation in comparison with that of a person whose situation has no cross-border element, and, if such a disadvantage is established in the present case, whether the national rule at issue is justified by objective considerations and is proportionate to the legitimate objective pursued by national law.