As voting began in the election to choose a new Labour leader, former prime minister Tony Blair today issued a warning to the party not to drift to the left.
Although he made no endorsement in his memoirs, published today, of any of the five candidates to succeed Gordon Brown, Mr Blair's comments will be seen as a mark of support for front-runner David Miliband over his brother Ed.
The shadow foreign secretary was today also boosted by the backing of the Labour-supporting Daily Mirror, which described him as the candidate the Conservatives "really fear".
In his memoir, Mr Blair left no doubt that he believes Labour lost the General Election in May because it "stopped being New Labour" under Mr Brown's leadership.
And he warned: "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. We have to buck the historical trend and face up to the reasons for defeat squarely and honestly."
Although his successor was "absolutely right" to intervene at the outset of the financial crisis to prop up banks and stimulate the economy, Mr Brown committed an "error" in going down the road of deficit spending, heavy regulation, income tax rises for the rich and big-state government, Mr Blair wrote.
He came close to endorsing the coalition Government's decision to pay down the bulk of the UK's deficit in the current parliament, warning that: "The danger now is this: if governments don't tackle deficits, the bill is footed by taxpayers, who fear that big deficits now mean big taxes in the future.
"If we fail to offer a convincing path out of debt, that failure ... will itself plunge us into stagnation."
In an apparent rebuke to leadership candidates who have fought on a platform of fighting the coalition Government's programme of public spending cuts, Mr Blair warned it would be "childish" and "out of touch" for Labour to define itself in opposition to its rivals.
"If Labour simply defaults to a 'Tory cutters, Lib Dem collaborators' mantra, it may well benefit in the short term," he wrote. "However it will lose any possibility of being chosen as an alternative government.
"Instead, it has to stand up for its record in the many areas it can do so, but also explain where the criticism of the 13 years is valid.
"It should criticise the composition, but not the thrust of the Tory deficit reductions."
Rather than simply attacking the coalition's cuts, Labour must offer plans to make different but "more radical" savings in government spending, said Mr Blair.
Failure to do so would leave the party in a position of "betting the shop that the recovery fails to materialise".
Mr Blair dismissed the suggestion that Labour could have formed a coalition with the Lib Dems in the wake of the indecisive result in May, insisting: "The people would have revolted; the votes weren't there."
But he said that there were many areas of policy where the Conservative and Liberal Democrat coalition partners "don't really agree", making them vulnerable to Labour if it sticks to the New Labour agenda.
The party must remain "flexible enough to attack the Government from left and from right", said Mr Blair.
He added: "Big-state politics today will fail. In fact, if you offer 'small-state vs big-state', small will win."
Mr Blair urged Labour's new leader to focus in opposition on "renewing the party" and "resisting any notion of letting the ... trade unions get back any dominance in policy".
He cited the "genius" of US President Barack Obama in reaching out beyond partisan divisions to build a progressive consensus around centrist politics.
Mr Blair revealed he told David Miliband in 2007 that he might beat Mr Brown for the leadership if he stood against him and turned the succession into a battle between Old and New Labour.
Mr Miliband - then environment secretary - approached him for advice shortly before his departure from office, but was "hesitant and, I felt, fundamentally uncertain as to whether he wanted it", said Mr Blair.
"He asked me if I thought he should stand and I said I couldn't make that decision for him," the former PM recalled.
"'What would happen if I did?' he asked.
"'I think you might win, not obviously but very possibly,' I replied.
"David thought, with good cause, that Gordon had it sewn up. I didn't think so actually and I also thought the moment there is a campaign and people start to flush him out, the ambiguities in his position, the gaps in hard thinking and also the trading off to the left would become apparent.
"Played correctly, it would put full square the choice of New Labour or not.
"But David was unconvinced. Some then and later criticised him for being too cautious. Personally I really sympathised ...
"I didn't blame him at all, but I did say he should be prepared in case the issue arose again, possibly sooner than we might think."
Mr Blair made no comment about Ed Miliband in his book, mentioning him only as a member of Mr Brown's circle. Andy Burnham has only one entry in the index and Diane Abbott none.
But the former PM was highly critical of the other contender for the the leadership, Ed Balls, describing him as "behaving badly" during his wrangles with Mr Brown and being "wrong on policy" over tax and Government spending.
And he suggested Mr Balls had little interest in appealing to the aspirational middle classes who Labour must win back in order to return to power.
"Ed Balls was and is immensely capable intellectually, and also has some of the essential prerequisites for leadership: he has guts and he can take decisions," wrote Mr Blair.
"But he suffers from the bane of all left-leaning intellectuals ... These guys never 'get' aspiration.
"They see the middle class - apart from the intellectual part of it - as an unnatural constituency for them ... They would think that a person worried about their tax rates was essentially selfish and therefore by implication morally a little lost.
"They could 'get' that it might not be smart to penalise them; but not that it might be wrong to do so."
Ed Miliband said Mr Blair and Mr Brown clearly had a "rocky relationship" but that it was also a "creative" one.
He told the BBC: "It was a rocky relationship, I will let Tony speak for himself about Gordon. I think both Gordon and Tony have been fantastic servants of our party and our country.
"But I think it is time to move on from Tony Blair and Gordon Brown and Peter Mandelson and to move on from the New Labour establishment and that is the candidate that I am at this election who can best turn the page.
"I think frankly most members of the public will want us to turn the page."
Mr Burnham said: "I have huge respect for Tony Blair and everything he achieved for Labour.
"But I am saddened that he has chosen this day of all days to publish his book.
"As ballot papers land, Labour should be looking to the future. Instead, senior figures in our party are rerunning the battles of the past through this leadership campaign.
"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.
"Now is the time for a new era for the Labour Party. I am proud of what we achieved and was equally loyal to Tony Blair and Gordon Brown.
"That is why I can move Labour beyond these stale old battles and create a new future for our party, building on the best of our past and leaving the worst behind."
Former deputy prime minister Lord Prescott warned of the "real danger" of Labour going into the wilderness for years if the leadership contest descends into a civil war between Blairite and Brownite factions.
When he and Margaret Beckett took on Mr Blair for the leadership in 1994, they did so on the basis that they were ready to serve under one another if they lost, he said, urging the current contenders to do the same.
Lord Prescott, who is currently standing for election as party treasurer, told BBC Radio 4's World at One: "The dangers are - as we saw with the Tories (after 1997) - that if the divisions continue and there is a suggestion that one (candidate) won't follow if the other is elected, that would be very, very damaging for us.
"It damaged Labour for 18 years, it damaged the Tories for 13 years."
Asked if internal divisions could damage Labour in the same way now, he replied: "If these wars were to continue, if that was the case.
"We have a fight now between 'Is it left, is it right, is it New, is it Labour?' Forget all that. Let's all be Labour and get behind the new leader."Reuse content