David Cameron's landmark plans to legalise gay marriage have emphatically passed in Parliament tonight, despite a majority of Conservatives failing to support the historic Bill.
An estimated 136 Tory rebels formed the vast majority of the 175 MPs who voted against the motion at its second reading in the House of Commons, with a few dozen more abstaining.
ITV News' Political Editor Tom Bradby reports on the split at the heart of the historic vote:
Northern Ireland Secretary Owen Paterson and Welsh Secretary David Jones voted against, while fellow Cabinet ministers Dominic Grieve and Philip Hammond stayed away.
But the rebellion was comfortably overwhelmed by 400 MPs supporting the bill to generate a majority of 225, a result that received huge applause from the public gallery.
Just 127 Conservatives endorsed the proposals at second reading.
There was a rebellion, too, on the evening's second whipped vote for the Bill's timetable, but the Government's programme motion was passed by 499 votes to 55 - a majority of 444.
Despite the division, MPs appeared to agree that allowing same-sex marriage would signal a major change in the life of the country.
ITV News' Special Correspondent Rageh Omaar visited Manchester to gauge the reaction to the potential changes there.
Responding to the vote result on Twitter, Mr Cameron wrote:
Strong views exist on both sides but I believe MPs voting for gay people being able to marry too, is a step forward for our country.
But those opposed to the Bill singled out the Prime Minister in the aftermath of the vote, which had followed a passionate afternoon debate from MPs across all parties.
David Cameron has split the Conservative Party in half on gay marriage and failed to win a majority of Tory MPs. Labour win.
Conservative ministerial aide David Burrowes said his party's split on the issue reflected the divided mood of the country and said the result had exposed Mr Cameron's political strategy.
Culture Secretary Maria Miller said the Conservative rebellion on plans for gay marriage came as no surprise to the Government.
Having been silent on an issue which had proved so publicly divisive for his party, the Prime Minister finally broke his silence barely two hours before MPs voted in the Commons.
In a televised statement, Mr Cameron said he respected those opposed to the legislation, but said establishing gay marriage would make "our society stronger".
But at the same time, a debate was closing that had heard a succession of Conservative MPs outline their opposition to the Bill upon its second reading.
The prominent Tory critics of the proposals argued the measures undermined marriage, would alienate voters and could damage the party's election prospects.
Mr Burrowes, a leading opponent, added that he had received death threats about his opposition to the measure and his children had been taunted and told "their dad's a bigot".
However, other Conservatives joined opponents across the floor to express their support for a Bill that they said would be a historic victory for equality.
Tory MP Margot James also warned that failing to enshrine gay marriage in law would see her party risk losing support in the next election, telling the House:
We may have gone two steps forward, but I fear we may have gone one step backwards. The modernisation of the Conservative Party is not yet complete.
Among the most passionate speeches came from former Labour minister David Lammy. He compared the current "separate but equal" laws, where gays could have civil partnerships but not marriages, to those faced by blacks in segregation-era United States.
Mr Lammy told the House why he was voting in favour of the Bill, despite some of his constituents telling him that the legislation was coming "too soon".
The emphatic result of the vote was welcomed by all three major party leaders.
Labour leader Ed Miliband - who saw 22 of his own MPs rebel against the legislation - said it was a "proud day", while Deputy Prime Minister Nick Clegg hailed a "landmark for equality".
Four of the 56 Liberal Democrats opposed the legislation at second reading - including former coalition minister Sarah Teather.
Deputy leader Simon Hughes and party president Tim Farron supported the Bill, but defied the whip to vote against the programme motion.
Attention will now turn to the Lords, where opponents of the plans are expected to mount tough resistance.