Cameron to lead the charge for a public vote on EU treaty

He announced he would table a motion for debate within weeks of Parliament resuming next month to put Labour and Liberal Democrat MPs on the spot.

His officials confirmed last night that he is likely to open the debate for the Tories, in an attempt to force the Prime Minister to defend himself at the dispatch box.

The Prime Minister has rejected calls for a poll on the EU treaty, despite a Labour manifesto pledge at the last election to put it to a vote.

But Mr Cameron believes the public is overwhelmingly in favour of a referendum and wants Mr Brown to honour his commitment.

He revealed that he is planning a parliamentary ambush designed to flush out Labour and Liberal Democrat MPs who are privately uneasy about the Government's refusal to offer a vote on the issue.

He said he was ready to "push the Government all the way on this issue".

The Tory leader added: "When Parliament returns we will hold an Opposition Day Debate and put down a very simple and clear motion to support a referendum on the European constitution."

He said both the Labour and LibDem manifestos in 2005 included an explicit pledge to hold a referendum on the discredited constitution, which collapsed after it was rejected by voters in France and Holland that year.

Labour and LibDem MPs should not be allowed to "break that promise", he told The Daily Telegraph.

"Every Labour MP fought the election on a manifesto that said in terms that we will have a referendum on the European constitution," he said. "Now this new treaty is the constitution in all but name according to the Spanish, Irish and French prime ministers.

"They have all said this is either 93, 95 or 98 per cent the same. It is absolutely clear the treaty is pretty much the same as the constitution. So that referendum should happen.

"Labour MPs should stick to what they promised. They should vote for our motion when we bring it forward in the House of Commons."

EU leaders agreed in June a new treaty which is almost identical to its predecessor, the constitution. They are to hammer out the final details at a summit in Lisbon in October.

Mr Brown has repeatedly rejected a referendum, arguing that EU leaders have abandoned all reference to a ' constitution' in the new text and British demands for a series of 'red lines' have been met.

But he has faced a drip-drip of calls from Labour figures for him to allow the public a vote, amid growing unease in Labour ranks that he risks being accused of a breach of trust with the voters.

Mr Brown has presented himself as a prime minister who will "listen" to the public.

Campaigners for a referendum expect only about 30 Labour MPs to back a referendum but are pinning their hopes on LibDem rebels and the House of Lords to put the Government on the spot.

Mr Cameron repeated his pledge to hold a referendum and campaign for a No vote if the Tories come to power in an early election that takes place before Parliament has ratified the new treaty.

"This is the wrong treaty, the wrong constitution for Europe," he said.

"It is about passing powers from Westminster to Brussels when actually what we ought to be doing is building a more flexible, open trading Europe, rather than moving in the direction of creating a European state."

Mr Cameron will use one of the Opposition Day Debates allocated to the Tories to raise the referendum. Although it will allow him to place the spotlight on the issue - and Mr Brown - Labour and LibDem MPs are unlikely to back a Conservative motion.