Lord Mandelson today issued a warning to Gordon Brown over the election as the Prime Minister's leadership once again came under threat.
A senior minister is said to be close to quitting in a move to destabilise Mr Brown, the Standard has been told.
There is speculation among MPs that a big beast such as Chancellor Alistair Darling, Lord Mandelson or Justice Secretary Jack Straw might be willing to tell Mr Brown to go if the party falls into fresh turmoil.
The Prime Minister was last under serious threat when James Purnell quit the Cabinet in June last year.
In an interview with the Standard, Lord Mandelson warned that Labour will lose if it fights the election with a core-vote strategy. “We are not a sectarian party. We are not a heartlands-only party,” said the Business Secretary.
Schools Secretary Ed Balls is said to back a strategy targeting voters in Labour's heartlands, but Lord Mandelson said: “We are not going to win the election on that basis.”
Labour is languishing about 10 points behind the Tories in the polls, and senior ministers have voiced alarm over what they see as a focus on the poorest and the trade unions. Lord Mandelson said Labour could only win by holding true to the strategy epitomised by Tony Blair's 1997 campaign, which reached out to Middle England and former Tories.
Asked about a core-vote campaign, he said: “It certainly does not represent Labour thinking or our strategy. Of course, we want to retain the vote thatis most loyal to us but we are not going to win the election on that basis. We have to reach out to the whole of the New Labour coalition that brought us support in the last three elections and without which we will not win the next.”
Tensions have been building in the Labour leadership for weeks over the shape of the election campaign. Mr Balls is credited with persuading the Prime Minister to adopt a strategy based on promising higher spending in schools and other key services, in contrast with Tory plans to cut expenditure.
Allies of Mr Balls deny he has pushed such a plan, and point to articles in which he has argued for Labour to stick with the coalition that re-elected Tony Blair in 2001 and 2005.
Lord Mandelson is said to have been angry that the pre-Budget report targeted the middle classes for tax rises and failed to spell out details of how spending would be cut to curb the deficit.
Along with Tessa Jowell, Mr Straw and Harriet Harman, he was dismayed when Mr Brown appeared to launch a “class war” campaign by joking that David Cameron's policies were “dreamed up on the playing fields of Eton”.
Lord Mandelson was seen to have withdrawn from the airwaves in the wake of the strategy, though his friends deny this.
Today he spoke out before he and the Prime Minister visited the site of a new super-port on the Thames Estuary near Thurrock. With a £1.5 billion investment by DP World, it will form Europe's largest combined deep-sea port and logistics park. The 1,500-acre park will create 12,000 construction jobs, and eventually 36,000 posts.
The Business Secretary hailed the project as “a vote of confidence in economic recovery”. During a walkabout, Mr Brown said: “Nothing that the Conservatives say adds up, and that's what the election is going to be about.”
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