Tony Blair has risked plunging the Labour leadership contest into civil war – by issuing a warning to the party not to drift to the left.
In his newly-published memoirs, the former prime minister says abandoning the New Labour agenda he spearheaded will spell defeat at the next election.
His comments – revealed on the same day as millions of ballot papers were sent out – were widely seen as support for leadership front-runner David Miliband over his brother Ed.
However, Mr Blair was careful in the book and in the interviews promoting it not to endorse any of the five candidates to succeed Gordon Brown.
David Miliband made no comment on the autobiography but his brother Ed said it was time to “move on from Tony Blair and Gordon Brown and Peter Mandelson” and claimed he was the candidate best placed to “turn the page” on that era.
Another contender, Andy Burnham, accused Mr Blair of “rerunning the battles of the past”, adding: “Labour needs to leave all this behind. Members are fed up with it. Most are not Blairites or Brownites, Old or New Labour. They are just Labour.”
Mr Blair’s book, entitled A Journey, lays bare the rift between himself and Mr Brown during his time in power, as well as his concerns about his chancellor’s fitness to follow him into 10 Downing Street.
Describing Mr Brown as brilliant but “maddening”, he blamed his successor for losing the general election in May by deviating from the New Labour message.
“Labour won when it was New Labour,” he wrote. “It lost because it stopped being New Labour.
“This is not about Gordon Brown as an individual. Had he pursued New Labour policy, the personal issue would still have made victory tough, but it wouldn’t have been impossible. Departing from New Labour made it so.”
Mr Blair said he knew before leaving office that Mr Brown could well be a “disaster” as prime minister.
He also revealed that he had advised David Miliband in 2007 that he might beat Mr Brown if he stood against him as a New Labour candidate for the succession.
Mr Blair wrote: “The danger for Labour now is that we drift off, or even move decisively off, to the left.
“If we do, we will lose even bigger next time.”
He delivered a harsh judgment on leadership contender Ed Balls – branding him someone who was “immensely capable intellectually” but had behaved badly and was “wrong on policy” – he could not understand the aspirational middle classes.
Although he backed Mr Brown’s interventions at the height of the banking crisis, Mr Blair said his successor then made the “error” of going down the road of deficit spending, heavy regulation, income tax increases and “big state” government.
Mr Blair also admitted he had been sceptical about setting up a Scottish Parliament and said he had never been “passionate” about devolution.
He also bemoaned the fact that, in the dying days of his administration, Alex Salmond was elected first minister – paving the way for the SNP leader to “play off” Holyrood and Westminster against each other.
Mr Brown made no response to Mr Blair’s account of their time in power.
However, former deputy prime minister Lord Prescott said the memoir presented only a “one-sided version” of their relationship.
He rejected the suggestion that Mr Brown had dumped the New Labour agenda and warned it would be “very, very damaging” for the party if the “wars” between Blairites and Brownites continued and leadership candidates refused to serve under one another.
Page after page of the memoir catalogues disagreements with Mr Brown and the “relentless personal pressure” from the then-chancellor for Mr Blair to quit.
In one of the most sensational passages, Mr Blair effectively accused Mr Brown of blackmail for threatening to trigger an investigation into the cash-for-honours affair if the prime minister did not back down in a row on pensions.
Within an hour of Mr Blair making it clear he would press ahead with pension reform, Labour’s treasurer at the time, Jack Dromey, had gone on TV to call for an inquiry.
Mr Brown denied having spoken to him and Mr Blair acknowledged he did not “know for a fact” that he had, but he added: “I couldn’t forget it and found it hard to forgive.”
Mr Dromey – the husband of acting leader Harriet Harman and now a Labour MP – did not respond to requests for a comment yesterday.
Labour MP Michael Dugher, a former Brown aide, said it was “slightly unkind and unfair” to brand his former boss a “strange guy” who lacked emotional intelligence.
Mr Brown could be “enormously emotional and friendly and engaging in a quite natural way” in private, Mr Dugher said.
Meanwhile, A Journey has become the fastest-selling autobiography in history, bookseller Waterstone’s said last night.