At the end of a full day's debate with more than 70 MPs supporting or opposing the bill on Tuesday, British lawmakers voted 400 to 175 in favour of allowing same-sex couples to marry.
More debates are expected to follow as the bill still needs to clear other stages in Parliament, including another vote in the lower and scrutiny by the upper house, the House of Lords.
If approved, the bill is expected to take effect in 2015 and enable same-sex couples to get married in both civil and religious ceremonies, provided the religious institution consents. The bill also lets couples who had previously entered into civil partnerships convert their relationship into a marriage.
The bill is strongly supported by Prime Minister David Cameron who allowed his colleagues a conscience vote on the issue. Cameron had described the move as "an important step forward" that strengthens society. The Times reported that the vote left Mr Cameron at odds with nearly 60 per cent of his MPs amid warnings from his backbenchers that the issue could cost him the 2015 election.
Read David Lammy's original speech that he had intended to give to the
House of Commons on 5 February 2013 on the subject of gay marriage
but faced a time limit.