Tory plea over EU treaty referendum

As Mr Brown prepares to agree the wording of the controversial document in Lisbon this week, the Tory leader challenged him to honour Labour's manifesto commitment to give the public a say on the constitution.

At the same time, the Prime Minister faced criticism from the president of the European Commission over Britain's "red lines" on criminal justice matters.

Jose Manuel Barroso told The Observer that the UK's opt-outs on policing and judicial co-operation - seen as essential to Mr Brown's attempts to sign the treaty without a referendum - would hinder the fight against terrorism.

Ministers insist a referendum is unnecessary as the current treaty is significantly different from the constitution which was rejected by French and Dutch voters in 2005. But critics insist the treaty is the constitution in all but name, while the cross-party Commons European Scrutiny Committee argued this week the two were "substantially equivalent".

In an article for The Sunday Telegraph, Mr Cameron accused the Prime Minister of betraying "trust and democracy" if he did not hold a referendum. "I think people are tired of being treated like fools by this Government, whether over the decision to cancel the General Election, the kind of tax con we saw again in this week's Pre-Budget Report, or the fake arguments in defence of the European constitution," he said.

Mr Cameron's call is backed by an ICM poll for The Sunday Telegraph which found that 66% of voters want a referendum and just 21% do not. In the event of a vote, 47% would oppose the treaty and 29% support it. Some 38% of the public would like Britain to quit the European Union altogether.

After a meeting with Mr Barroso on Thursday, the premier vowed he would not sign up to the treaty without Britain's "red lines" intact. He said the national interest would come first and, without opt-outs in areas like criminal justice and social security, he "could not accept" the treaty. "I make that absolutely clear," he said. "If we achieve the red lines... then we will be prepared to accept it."

But Mr Barroso expressed irritation with Britain's stance. "Sometimes it appears as a contradiction," he said. "Britain, which is always first to ask for global action against terrorism, appears not to be as committed as other members of the EU when it comes to Europe. This surprises me."

He added that he would prefer not to have any opt-outs: "To fight international terrorism and crime, we will need more, not less, co-ordination and integration."