Brown enjoys biggest lead for years

In a major boost to Gordon Brown, the ICM survey for the Sunday Telegraph put Labour on 40% compared with 33% for the Tories and 19% for the Liberal Democrats.

The seven-point lead - its biggest since September 2005 - came as it emerged that key Cabinet ally Ed Miliband had been set to work on Labour's general election manifesto. The process is expected to continue through the autumn, but will fuel speculation that the Prime Minister could go to the country next spring - two years before an election is necessary.

Poll findings such as ICM's, which would be enough to give Mr Brown a majority of more than 100 seats, may persuade him to strike early.

Mr Brown made an audacious grab for Tory support on Saturday when he invited "moderate Conservatives" to join the Labour Party. His appeal follows the defection to Labour of Tory MP Quentin Davies and Mr Brown's attempts to build a government of "all the talents".

But Mr Brown's first by-election test, in Ealing Southall next Thursday, has been beset by defections to the Tories by a series of local Labour councillors.

In his first speech as Prime Minister to Labour's National Policy Forum, Mr Brown insisted Labour had to have the confidence, "to shape and enlarge the centre ground" around the party's values.

In a pointed appeal to Tories, he went on: "As we reach out to those who share our vision of a better Britain of rising aspirations and new and better opportunities, I urge all who share our values - from progressives in all areas of Britain to moderate Conservatives - to join us in making Britain the country it can be."

Mr Brown also promised a series of initiatives on housing, welfare and younger people in the weeks ahead. Work and Pensions Secretary Peter Hain is to announce an extension of the New Deal which would match up the hardest-to-reach unemployed with job vacancies.

ICM Research interviewed a random sample of 1,003 adults by telephone on July 11 to 13. Results were weighted to the profile of all adults.