Neil Dalgleish, partner of Ben Bradshaw, MP for Exeter since the general election, will be able to visit the House of Commons when he wishes.
This unprecedented recognition of his role is likely to mean that Mr Dalgleish, 33, a London-based journalist, will be able to claim concessionary rail travel and other privileges hitherto reserved for heterosexual partners and families.
Spouses are allowed special passes to gain admission to the precincts of the Commons, including some of the bars and restaurants, the underground car park and the gymnasium.
The move is understood to have been authorised by the Serjeant at Arms, who is responsible for administration and security within the palace of Westminster.
Mr Bradshaw, 36, is one of three openly gay Labour MPs in the Commons. Chris Smith, the Heritage Secretary who "came out" several years ago, was joined after the 1 May election by the Exeter MP and by Stephen Twigg, the MP for Enfield and Southgate who ousted Michael Portillo.
But Mr Bradshaw is the first to seek a "same-sex" Commons pass. He said the Commons authorities were "extremely gracious and very efficient".
The Labour Party declined to comment last night, saying it was "a matter for Mr Bradshaw and the Serjeant at Arms".Reuse content