Simon Hughes, the deputy leader of the Liberal Democrats, has said that the government will give gay couples the right to civil marriage.
He predicted that the change would be made before the next general election.
Mr Hughes said a consultation would take place in the coalition government on taking civil partnership to the next level.
Speaking in a video interview, he said: “It would be appropriate in Britain in 2010, 2011, for there to be the ability for civil marriage for straight people and gay people equally.
“That’s different of course from faith ceremonies which are matters for the faith communities… they have to decide what recognition to give.
“The state ought to give equality. We’re halfway there. I think we ought to be able to get there in this parliament.”
Currently, gay couples in the UK can have a civil partnership, which is not called marriage. They may not have a religious ceremony.
However, the coalition government is coming under increasing pressure to provide full marriage equality as other countries around the world make the step.
Prime minister David Cameron is on record saying that he will consider the change, while the most senior gay Tory, Nick Herbert, told PinkNews.co.uk on Saturday: “Well as you know, what David Cameron and George Osborne said just before the election was that gay marriage is something that we should look at, in time.”
“It’s not something we’ve got immediate plans to change, but we recognise that there are views that say that the name is important.”
To see a video clip of the interview, scroll down.