A heterosexual couple have lost their Court of Appeal battle for the right to enter into a civil partnership instead of a marriage.
Rebecca Steinfeld and Charles Keidan, from London, challenged a ruling that they could not have a civil partnership because they did not meet the legal requirement of being the same sex.
The couple had argued that this meant they faced discrimination.
But the Court of Appeal dismissed their challenge.
The BBC’s legal affairs correspondent Clive Coleman said the couple had lost by the “narrowest of margins” as all three judges accepted that there was a potential breach of their human rights.
Ms Steinfeld, 35, and Mr Keidan, 40, want to secure legal recognition of their seven-year relationship but have said that marriage is not suitable for them.
The academics, who live in Hammersmith, west London, and have a 20-month-old daughter, say that the government’s position is “incompatible with equality law”.