Slinking off into the shadows, he returned as the Comeback Kid and then, when no-one was looking, he snatched an unlikely cameo as Gordon Brown's right-hand man.
His latest incarnation, and one entirely of his own making, is as storyteller. Dressed in a smoking jacket for the advert to promote his memoirs, The Third Man, there was still a hint of the pantomime villain as he told of two rival kings, an evil prince and a kingdom divided. Today he's in more earnest mood and insists his decision to expose the rift between Tony Blair and Gordon Brown and the policy differences which caused New Labour to implode was more than just an attempt to regain the spotlight.
"I wanted people to both know the truth about me, my lifestyle and my political motivations," he says, in almost hushed tones. "When you are in government so much is written about you, so much is said over which you have no control, I don't think people know what it is that actually makes me tick."
Mandelson has dedicated The Third Man to his parents, Mary and Tony, who he says gave him his "values and the best upbringing anyone could wish for", but while the book gives a nod to his Hampstead childhood where his neighbours were Labour stalwarts like Hugh Gaitskell and Michael Foot, at its heart is the rollercoaster years which took the party from impossible highs in 1997 to unprecedented lows, ending in defeat at the last General Election.
Mandelson's own career has been similarly rocky. Twice sacked from the Cabinet, once in 1998 after it transpired he had used a secret loan from ministerial colleague Geoffrey Robinson to buy his Notting Hill home and again in 2001 amid allegations of misconduct over a passport application for the Hinduja brothers, who had supported his pet project, the controversial Millennium Dome. Mandelson was later cleared of any wrongdoing, but in the 18 years since he first took the seat for Hartlepool, he has witnessed and been part of an immense shift in Britain's political landscape.
"I had a ringside seat and most of the time I was actually in the ring," he says. "Of course, I would have liked my own career to have run a little more smoothly than it did. I could done with a few less sleepless nights, but when I look back I do feel privileged to have had an insider's view of Westminster."
As early extracts of his memoirs, which claimed Blair had described Brown as "mad, bad and dangerous" and cast Nick Clegg as New Labour's executioner, emerged last week, many began to question Mandelson's true intentions behind a book which would inevitably rake up old problems. To some, it felt like he was kicking a tired old dog when it was already down.
Unsurprisingly, Mandelson disagrees. He says he went to press before the Labour leadership race was decided to allow time for the dust to settle and gives the impression The Third Man is his way of doing Labour a final big favour. He sees it not as some political kiss and tell, but as a helpful guide on how to get into government and stay there.
"Labour has to understand the pace of change, it has to make itself relevant in the future," he says. I wanted people not only inside the party but outside to know what really happened because there is a lot to learn from our success and our failures. If we are to go forward we can't allow problems to be swept under the carpet. A lot of memoirs tend to be very self-congratulatory, I didn't want that. I wanted a honest straightforward account. I wanted to be transparent."
Mandelson is aware enough to know that his critics – and there are many – will choke on this sudden rash of honesty from the man, who along with Alastair Campbell, made spin
doctoring a full-time
profession. By way of showing perhaps he means it, on
Monday he will begin to post
his entire 25 year political archive on the internet, warts and all.
"Some might say I've been too graphic in my telling of New Labour's story, but I don't agree," he says. "I respect the people I have worked with and I did use a certain amount of discretion when it came to writing about private conversations.
"It's about learning lessons. The rift between Brown and Blair was avoidable. It didn't have to be a car crash. It's always portrayed as a clash of personalities and it was at one level, but more importantly it was a clash of political ideals of how radical and quickly the party needed to change.
"When you have two people on opposite sides, there is a tendency for the rest of the party to unite around the wrong things. That's what we happened in the 1980s and that's what happened in the latter years of the administration."
Mandelson has a tendency to make it all sound like a terrible misunderstanding, but his book doesn't paint a particularly edifying picture of parliament. From the personal power struggles to launch of Operation Teddy Bear, a Blair-inspired plot to split the Treasury in two and weaken Brown's position, it often feels like the electorate were forgotten as politicians sort to protect their own self-interest.
"Let me stop you there," says Mandelson, insisting I've misread the situation completely. "When I returned to government in 2008, the one thing I noticed was a complete absence of acrimony. The party was still as united as it had been under Blair and that is no mean feat. Compare that to Margaret Thatcher, who went to war
with not only her Chancellor, but her Foreign Secretary. That was a government which had poison it ."
We're now back on familiar territory, but even the ever self-assured Mandelson admits to having at least a few regrets
when he looks back over the last 13 years.
"We achieved a lot in terms of the health service and education, but we could have and should have done more," he says. "When you have three such huge election victories, a touch of hubris can enter the soul.
"It's something you have to guard against and perhaps we didn't guard quite fiercely enough. We might have been okay, but when the banking crisis hit and amid the ensuing recession, it was too much.
"We did invest in science and in skills, but I wish now what I called industrial activism had been operating from the beginning. As a government we needed to recognise much more how policies impacted on businesses, that realisation came too late.
Mandelson remains adamant that Brown will ultimately be remembered not as the dour Scot or the PM who forgot to switch his microphone off
when talking to Gillian Duffy on the campaign trail, but as the man who fought back against the financial crisis.
But what about New Labour? The party's flagship initiatives like Building Schools for the Future have already been shelved, companies like Sheffield Forgemasters, whom Mandelson himself promised an 80m government loan, have been told there is no cash and the public sector is braced for ferocious cuts. Was the final Labour Cabinet guilty of signing cheques, in one last pre-election hurrah, they knew could never be cashed?
"I pledged that money to Forgemasters for a reason,"
he says. "I don't think a government should protect every private business concern, but you do need to identify areas where help is needed. Forgemasters was one of those industries. The fact the loan has been scrapped not just by the Conservatives, but aided and abetted by Nick Clegg, is very hard to stomach. He should know better.
"What is happening now is a huge mistake and one the country will pay for not just now or in a few years, but for the next decade."
Mandelson has refused to be drawn on the leadership
debate, although many
suspect he'd be happiest with David Mililband.
"Whoever it is will need to have experience of a ministerial office," he says. "They will
need to have fresh ideas and
be made of tough stuff. Politics
is a life of hard knocks and it's only by being tough that you succeed.
"As for me, I need to earn a living, but if there is another Labour government, I would like to be considered for membership of it."
Given his talent for reinvention, what Mandy does next is anyone's guess.
The Third Man: Life at the Heart of New Labour is published by Harper Press, priced 25. Peter Mandelson will be in conversation with David Aaronovitch at the Queens Hotel in Leeds on Wednesday at 7pm. For tickets call Waterstones in Leeds on 0113 244 4588.