Prime Minister Gordon Brown slipped behind the Conservatives in an opinion poll published on Sunday, a new blow to hopes that his economic stimulus plan would revive his political fortunes.
The Ipsos Mori poll for the Observer newspaper showed the Conservatives stretching their lead to 11 points.
An ICM survey for the Guardian newspaper on Saturday had given the Conservatives a 15-point lead.
The two polls are a sharp contrast with a YouGov poll on Wednesday which said Brown had actually cut the Conservative lead to just four points.
The Ipsos survey was conducted two days after the government announced plans for a 20 billion pound package to boost the economy, including a temporary cut in Value Added Tax (VAT) to 15 percent.
It put David Cameron's Conservative Party on 43 points, up three, and Brown's Labour Party down five to 32 points.
The lead, if repeated at an election, would give the Conservatives a substantial parliamentary majority. Brown does not have to go to the electorate until 2010.
To add to Brown's woes, the survey also showed that only six percent of respondents would spend more after the VAT cut while 26 percent said they would reduce purchases.
http://uk.reuters.com/article/UKNews1/idUKTRE4AS03V20081130