British members of parliament have overwhelmingly voted for a historic bill allowing gay marriages in the United Kingdom. At the end of a charged debate in the House of Commons last night, they voted by a majority of 400 to 175 to redefine marriage and allow same-sex couples to tie the knot.

The first gay marriages will be conducted once it becomes law later this year after it is cleared by the House of Lords. At present same-sex couples only have the option of a civil partnership, which offers the same legal rights and protections on issues such as inheritance, pensions, and child maintenance.

The move, however, also exposed the rift within the Conservative Party, as Prime Minister David Cameron failed to get a majority of his own MPs to support the move.

Over 136 Tories declined to support the government on an issue the party chief had personally invested in. Just 132 supported the measure and there were 75 abstentions to the Marriage (Same Sex Couples) Bill.

Cameron, who had been urged to shelve the vote to avoidexposing party divisions on the  issue, said that while ‘strong views’ existed on both sides, he believed voting for gay people being able to marry was ‘a step forward for our country’.

“Marriage helps people commit to each other and I think it is right that gay people should be able to get married too. This is, yes, about equality. But it is also about making our society stronger,” he said, in an impassioned television plea hours before the debate.

The bill had the backing of the majority of coalition partner Liberal Democrats and Opposition Labour MPs. Liberal Democrat chief and Deputy Prime Minister, Nick Clegg described the result as a ‘landmark for equality in Britain’ which showed “no matter who you are and who you love, we are all equal”.

Opposition labour leader Ed Miliband said, “This is a proud day and an important step forward in the fight for equality in Britain. The overwhelming majority of Labour MPs supported this change to make sure marriage reflects the value we place on long-term, loving relationships whoever you love.”

However, opponents within the Tory party have vowed to fight on. Conservative MP David Burrowes said more people would oppose the bill as it progressed through the Houses of Parliament.