The first same sex marriages under the recent legislation are expected in summer 2014.

Pension schemes will have to treat surviving same sex spouses the same way as surviving civil partners. This means contracted-out benefits must be based on contracted-out service since 1988; other benefits need only be based on service from 5 December 2005.

But these requirements could change. First, the legislation obliges the government to review the differences between the benefits that must be paid to survivors of the various opposite and same sex relationships that the law now recognises. Its report, which is due by the end of June 2014, must also examine the cost of eradicating them.

Secondly, an appeal is expected in Walker v Innospec. This is the case in which the Employment Tribunal held it was unlawful discrimination for a scheme to restrict a surviving civil partner’s benefits to post 5 December 2005 service when a spouse’s pension would be based on a longer period. The Tribunal held the legislation allowing this was at odds with EU equality law. If the decision is upheld on appeal, the legislation on civil partners - and same sex marriage - is likely to be changed.

That said, many schemes go beyond the legislation and already treat civil partnerships and marriages the same way.

Overall it appears only a matter of time before the law requires survivors of either sex in whatever kind of formal union to be treated the same.