Two thirds of Britons want to have a referendum on the new European Union reform treaty - including a majority of supporters from the main political parties, according to an exclusive YouGov poll.
The treaty has ignited fierce opposition, with critics claiming it amounts to little more than a revived version of the old EU Constitution, which was abandoned after being rejected in referendums in France and the Netherlands.
Last week, it emerged that Denmark could hold its own poll and Scotland and Northern Ireland could move towards consultative polls despite the entrenched opposition from Gordon Brown.
The Prime Minister is under pressure because of a Labour commitment in its 2005 manifesto to hold a national vote on the EU Constitution before it was halted by the French and Dutch votes.
The survey, commissioned by The Daily Telegraph, found that 64 per cent of all voters thought there should be a national referendum on whether Britain should ratify the new EU treaty.
Only 12 per cent thought there should not be a national vote on the treaty.
YouGov polled 2,165 electors across Britain between Wednesday and Friday, as Labour's annual conference was coming to a close.
The study found a majority in every major political party in favour of a referendum, from 85 per cent of Conservative voters, to 55 per cent of Labour supporters and 59 per cent of Liberal Democrat voters.
Just six per cent of all voters thought "the new treaty differs substantially from the old constitution and no longer contains most of the provisions that many people objected to two years ago".
Mark Francois, the shadow Europe minister, said the poll showed "beyond doubt that there is overwhelming public support for a referendum".
The cross party campaign, I Want a Referendum, signed up more than 500 party activists and delegates at the Labour, Liberal Democrat and TUC conferences over the past three weeks.
Paul Stephenson, a spokesman, said: "This issue is bigger than narrow party politics — it's about democracy. If Gordon Brown refuses to listen to the people it will hurt him in the next general election."
Last week, in a surprise move in Denmark, the power-sharing Conservative party called for a referendum on the EU's treaty, saying it was "idiotic" not to.
A spokesman said: "We have nothing to hide and it would be idiotic to act as if we had. It would only cement a faulty perception among the people."
Pressure has also come from local parishes, which have been organising their own local referendums. Broughton Astley, Leics, has become the latest to call a referendum, asking its 7,000 adults next month: "Do you want a national referendum on the EU Reform Treaty?"
William Hague, the shadow foreign secretary, is likely to address the issue when he speaks at the Tory conference in Blackpool tomorrow.
The number of readers who support The Daily Telegraph's campaign for a referendum totals more than 102,500. The campaign is now one of the biggest in the newspaper's 152-year history.
Despite critics claiming the new treaty contains "90 per cent" of the Constitution, Mr Brown has refused to offer the British public a referendum before its introduction.
Mr Brown will head to Brussels on Oct 18 to agree the treaty, ahead of the formal signing in December.