By Ian Dunt
Peter Mandelson has faced criticism from across Labour after backing David Miliband in the leadership contest, suggesting his influence is on the wane after nearly a generation as one of the party's most important figures.
The former spin doctor and business secretary attacked the centre-left message of Ed Miliband to the Times while at the Edinburgh book festival, saying he was wrong to brand New Labour a 'comfort zone'.
"I think that if he or anyone else wants to create a pre-New Labour future for the party then he and the rest of them will quickly find that that is an electoral cul-de-sac," the peer said.
"We're a political party, not a church, and we require the support of voters actively to embrace us, and if we stop recognising that, then we're going to be taken back into those long years of opposition that served us and the country so ill.
"If you shut the door on New Labour you're effectively slamming the door in the faces of millions of voters who voted for our party."
David Miliband was quick to disassociate himself from the comments, saying: "Party members, including me, are sick and tired of the old battles of the past being rerun. It's time to move on."
Ed Miliband hit back through his campaign agent, Sadiq Khan, who branded the Mandelson comment part of the unpleasant Labour tradition of 'attack machine' politics.
"This leadership election, in its final few days, is coming down to a stark choice between the New Labour past or Ed Miliband's plan to change the party and reach out to those we lost since 1997," he said.
"Party members and the public will not be convinced by hearing the same old messages from the New Labour attack machine being used against one of our leadership candidates."
Mandelson retorted with a reference to the lessons the New Labour architects such as himself and Tony Blair learned during the party's long period in opposition.
"This is not about so-called 'attack machines' for goodness sake, it's about grown-up politics and how Labour is to win a future election," he said.
"Ghettoising the party is not a winning strategy. I am sorry if this is regarded as an 'old message' but it is a lesson I learned during 18 long years of opposition before 1997."
Alistair Cambpell said the contribution was "as unwise as it was unwelcome".
Ex-Labour leader Neil Kinnock said Lord Mandelson was "sadly out of date". Speaking later to the Western Mail, he even suggested the former business secretary was going through a "midlife crisis".
Diane Abbott, who is to the left of the other candidates in the race, told Radio 4's World at One: "Lord Mandelson is a man of great talents but he does have to accept that his era is over and the public do not want a return to the spin, the triangulation and internecine warfare that characterised that era."
Meanwhile, Ed Balls criticised the "daily episodes" of the Miliband "soap opera" which the leadership race had descended into in recent weeks.
The shadow education secretary made the comments while campaigning for a £6 billion investment in affordable housing.
The row over Lord Mandelson's comments serves as stark evidence of how quickly the former spin doctor's star has fallen since leaving office.
Many Labour figures were irritated by the frankness of his memoirs, which were prepared at record speed following the fall of the Labour government so they could be released before Tony Blair's.
But the reaction to Lord Mandelson's comments has as much to do with Mr Blair as it does with him.
The timing of Mr Blair's memoirs publication tomorrow could not come at a worse time for the leadership candidates. That is especially true for David Miliband, who is most closely associated with Blairism.
Mr Blair remains a highly divisive figure in the Labour party and the dredging up of old wounds will only hinder David Miliband's chances of convincing those on the centre and left of the party to lend him their support.
In a neat coincidence, voting for the leadership begins tomorrow, on the same day the Blair memoirs are released, and continues until September 22nd.