David Cameron's ploy to quash a Tory rebellion over the EU has failed miserably, with 115 Conservative MPs voting for a motion "expressing regret" that no EU referendum was included in the Queen's Speech.
Ten Labour MPs also voted for the bill expressing disappointment that a referendum was not included in the government's plans for the year ahead.
Although the House of Commons vote to reject EU Referendum Amendment to Queen's Speech was rejected with a majority of 147 votes (277 votes to 130) the unusually large number of Tory MPs who rebelled shows David Cameron's attempt to buy off eurosceptic MPs with a draft bill has failed miserably.
In a public dig to the PM, Tory MPs have been tweeting their support for the amendment that "regretted" the lack of an EU referendum bill in the Queen's Speech.
Conservative MP Peter Bone, who tabled the amendment, told the BBC that MPs were not defying Cameron but rather were urging the government to introduce legislation for a referendum.
He said: "It shows that the Conservative Party wants an EU referendum. No Conservative voted against the amendment, many Labour MPs voted for it."
He added: "This is not a rebellion, this is a free vote. In fact, to a certain extent, the Prime Minister was encouraging us to vote for the amendment because, after all, it's his own policy."
David Cameron insisted nothing could be read into the result because he had allowed backbenchers a free vote but Labour claims he has "completely lost control" of his party on the issue.
Speaking to journalists at the UN, Mr Cameron said: "I don't think people can read in anything really to the scale of that free vote.
"Not least because only the Conservative Party has a very clear position and a very clear policy about what needs to happen in Europe."
Mr Cameron promised an in/out referendum by the end of 2017 earlier this year but eurosceptics want the commitment written into law and the leadership yesterday published a draft Bill that would enable that to happen. It would have to be taken up by a Tory backbencher to get the plan considered in Parliament, but opposition from Labour and the Lib Dems would prevent it making progress.
Tory backbenchers were given a free vote on the referendum amendment to the Queen's Speech motion - which is non-binding - although Conservative ministers were instructed to abstain.
Mr Cameron, who missed the vote because he is on a visit to the United States, denied he had been panicked into publishing the draft Bill to try to quell the Tory unrest and was "profoundly relaxed" about the situation.
He insisted he had always accepted the need to do whatever was possible to strengthen his pledge to hold an in/out referendum before the end of 2017.
Earlier, Nick Clegg, standing in for the Prime Minister at question time in the Commons, dismissed Tory calls for a Bill paving the way for a public vote on remaining within the EU and complained about Conservative criticism of the Queen's Speech.
The Deputy Prime Minister said: "My party has always believed that there should be a referendum on Europe when the rules change, when new things are being asked of the UK within the EU.
"That's what we had in our last manifesto, that's what we have now acted on in Government by passing legislation, together in the coalition, just two years ago, giving an absolute legal guarantee in legislation for the first time ever that when the rules change there will be a referendum - and by the way I think it's a question of when, not if, because the rules are bound to change.
"I suggest that we should stick to what we have done as a Government in giving that guarantee to the British people rather than constantly shifting the goalposts."