David Ashby, the Tory MP who last year lost a libel case involving allegations of homosexuality, voted with Labour to defeat the Government to give gay couples the same right to inherit the tenancy of their homes as heterosexuals.
In a Commons committee on the Housing Bill, Mr Ashby voted for an amendment put by Glenda Jackson, Labour MP for Hampstead, which would give same- sex partners the right to succeed to a tenancy if they have been living together for more than 12 months and the partner who holds the tenancy dies.
Mr Ashby's switch overturned the built-in Tory majority of one on the committee. Ms Jackson welcomed the move as a "simple matter of justice", and said she would write to the Prime Minister to ask him to back the committee's decision.
It is likely, however, to be reversed in a vote of the full House of Commons, with the support of the Ulster Unionists, although there could be a further revolt from Tory gay rights supporters such as Edwina Currie and Michael Brown, the only acknowledged gay Tory MP.
Mr Ashby said: "Why should we not allow succession? What is fundamentally wrong? Are not we in a society that is changing? And if it is not changing, should not we in Parliament be changing it?"
Under existing law, only married or heterosexual couples can succeed to tenancies on death.Reuse content