LONDON (Reuters) - The Conservatives enjoyed their strongest support for 15 years on Sunday with the latest opinion poll capping a bruising week for Prime Minister Gordon Brown.
Brown had enjoyed a honeymoon period with voters during his first 100 days in office but his comfortable 11-point poll lead has now evaporated in the face of a policy onslaught by Conservative leader David Cameron.
Brown was pilloried in the press and by the opposition after deciding last weekend not to call a snap election two and half years early.
The ICM poll for the Sunday Telegraph showed the Conservatives on 43 per cent, seven points ahead of Labour on 36. The Liberal Democrats trailed in a distant third with 14 percent.
The Conservatives, trounced in the past three elections by Brown's predecessor Tony Blair, have seized the initiative with a string of popular tax-cutting policies.
In sharp contrast, Brown was widely derided for fuelling election fever only to back off when his comfortable opinion poll lead evaporated.
Brown's Chancellor Alistair Darling was then accused of stealing Conservative policies when he unveiled new inheritance tax cuts in his pre-budget report.
Cameron, under attack from right-wingers in his party until his fortunes were sharply reversed, renewed another line of attack on Sunday -- over the European Union.
"I think people are tired of being treated like fools by the government, whether over the decision to cancel the general election, the kind of con we saw in this week's pre-budget report or the fake arguments in defence of the European constitution," Cameron wrote in the Sunday Telegraph.
Brown, who replaced Blair as premier in June, is under strong pressure to give voters a referendum on the EU treaty. He is being urged to do so by the Conservatives, newspapers and some members of his own Labour Party.
Blair offered voters a referendum on the old EU constitution, rejected by French and Dutch voters in 2005. But Brown argues the new treaty is far less ambitious.
Brown has said he had to be absolutely sure British national interests were safeguarded in negotiations on the treaty that are due to wrap up at an EU summit in Lisbon.
The treaty provides for a long-term EU president, a stronger foreign policy chief and a more democratic voting system.