David Cameron was on Monday licking his wounds after the largest parliamentary rebellion of his premiership as 79 Tory MPs voted in favour of a referendum on Britain's relationship with Europe.
The government won the House of Commons vote late Monday by 483 votes to 111 due to support from the Liberal Democrats -- the Tories' euro-friendly junior coalition partners -- and the main opposition Labour Party.
But in the biggest show of internal dissent in his 18 months in charge, the Tory eurosceptic wing ignored Cameron's plea that it was the wrong time for a referendum because of the debt crisis engulfing the eurozone.
After helping orchestrate the biggest ever Conservative rebellion over Europe, senior backbench lawmaker Mark Pritchard insisted it would become "more rather than less of an issue" over the rest of the parliament.
The Daily Mail newspaper's front page described the result as a "Bloody Nose for Cameron", while Tim Montgomerie, editor of the ConservativeHome blog which represents grassroots Tories, warned it had crystallised party divisions.
Many traditional conservatives were already unhappy with Cameron over the sacrifices required to form a coalition with the Lib Dems, as well as his efforts to rebrand the party as "compassionate conservatives".
"Unless Cameron becomes a lot more collegiate, it's only going to get worse," Montgomerie wrote in The Guardian.
The euro-sceptic Daily Telegraph added: "The prime minister will survive this battle, but the way he sought out the fray and the weapons he chose to wield will ensure it is not his last."
The vote took place against a backdrop of intense negotiations on the eurozone debt crisis, which prompted French President Nicolas Sarkozy to criticise Cameron for interfering during a stormy EU summit on Sunday.
Cameron returns to Brussels on Wednesday for a European Council meeting which he insisted was needed to protect the interests of non-eurozone members.
On the same day, the 17 countries using the euro hope to thrash out a plan to boost confidence after months of indecision and uncertainty that have shaken the currency.
Official figures show 79 of the Conservative party's 305 lawmakers voted against the government with two abstaining, in the biggest rebellion over Europe in the history of the party of Margaret Thatcher.
In 1993, 41 MPs defied then-leader John Major over the Maastricht treaty.
Cameron's Downing Street office defended his decision to force through what many commentators believe was an unnecessary confrontation with backbenchers.
A spokesman repeated the premier's argument that Britain benefited hugely from being in the EU, adding that he was determined to bring about "fundamental reform" in the 27-nation bloc.
But Labour leader Ed Miliband described the result as "a humiliation" for Cameron.
Members who defied the three-line whip -- the strictest party device used in parliament -- are likely to face internal disciplinary action, and one ministerial aide, Adam Holloway, quit before he was pushed.
Although the vote was not legally binding, polls suggest the rebels had the public on their side.
A ComRes survey on Monday revealed that 68 percent of Britons support a national vote on EU membership, while an ICM poll published on Tuesday found 49 percent want to leave Europe, compared to 41 percent who want to stay.
Opening the debate on Monday, Cameron said he sympathised with those who wanted a new relationship with Brussels, but said the eurozone debt crisis meant it was the wrong time to debate leaving the EU.
"It's not the right time, at this moment of economic crisis, to launch legislation that includes an in-out referendum," he said.
"When your neighbour's house is on fire, your first impulse should be to help him put out the flames."
The proposed referendum would have asked the British public if they wanted to remain in the EU, leave or renegotiate membership, in the first such vote since 1975.