The Supreme Court has ruled that benefits for same sex spouses must be provided on the same basis as for opposite sex spouses and that the exemptions contained in the Equality Act 2010 are incompatible with EU law and must therefore be disapplied.

Mr Walker had brought a challenge regarding benefits payable to his spouse (under a civil partnership). The benefits payable from his former employer's pension scheme were limited so that only pensionable service after 5 April 2005 would count for the purposes of calculating any survivor's pension for a same sex spouse or civil partner. This meant that if he predeceased him his spouse would receive a pension of around £1,000 per annum as contrasted with a pension of £47,000 per annum if pensionable service before 5 April 2005 was included.

The Court of Appeal had concluded that service before 5 December 2005 did not need to be counted. The Court of Appeal found that civil partnership was comparable to marriage but rejected Mr Walker's appeal nonetheless. The Court of Appeal referred to the EU legal principles of 'no retroactivity' and 'future effects'. The principle of 'no retroactivity ' was described by Lewison LJ as prescribing that EU legislation did not have retroactive effect unless, exceptionally, it is clear that the legislator intended this, that the purpose to be achieved requires this and that legitimate expectations of those concerned are duly respected. The Court of Appeal concluded that the principle of no retroactivity meant that the prohibition on discrimination only applied in respect of pensionable service and contributions paid before 2 December 2003 (the deadline for transposition of the Equal Treatment Directive into domestic legislation).

The Supreme Court allowed Mr Walker's appeal on the grounds that the temporal limitations contained in the Equality Act were incompatible with EU Law. Lord Kerr concluded that inequality in treatment arises when the entitlement to pension arises. He disagreed with the Court of Appeal's conclusion that the entitlement is 'permanently fixed' as it accrued. The judgement follows the thinking in other recent CJEU cases including Maruko. In Maruko, the CJEU concluded that same sex couples are in a comparable position to married couples and therefore that it is direct discrimination to treat them less favourably.

The Supreme Court referred to the Barber judgement, which was limited in application to pensionable service after 17 May 1990. The Barber judgement was described as exceptional in its temporal application and was not regarded as relevant in respect of the Equal Treatment Framework Directive.

This is more likely to be an issue for schemes providing pensions on a defined benefits basis. When the legislation on civil partners and then same sex marriage were introduced, many employers introduced death benefits for same sex spouses (including civil partners) so that they were provided on the same basis, without any service limits, as opposite sex spouses' pensions were already provided for.

However, some employers will have followed the legislative requirements and limited death benefits for same sex spouses (including civil partners) so that no benefits other than contracted out benefits would be payable in respect of service before 5 December 2005. Employers will need to revisit this and ensure that benefits are provided from their pension arrangements on the same basis for same sex spouses (and civil partners) as it is for opposite-sex spouses.

If UK compliance with the Equal Treatment Directive is no longer needed once withdrawal from the EU is complete, then in theory the Equality Act 2010 or parts of it, could be withdrawn as part of the review of legislation taking place within the European Union (Withdrawal) Bill. This will depend on government policy in this area. Equality is not a matter which is simply an EU matter so it would be surprising if the government sought to unravel developments in this area.