It is widely believed that I left my job with Gordon Brown because I took the rap for leaking details of Mandelson's home loan that got him sacked the first time, back in 1998.
In fact, Brown and I recognised that my sort of spinning had had its day and that Brown was better off without me.
Being blamed for Mandelson's downfall just meant I left in a blaze of publicity and made me a hero with Labour activists.
Blair, on the other hand, couldn't do without his chief spin doctor - Mandelson - who the rest of the Cabinet think should never have been allowed near a red box in the first place.
Blair just couldn't see that it was Mandelson who was responsible more than anyone for the public being sceptical about anything the Government said. In his book Mandelson now says: 'The Government must at all times be scrupulous with the facts and what it tells the public.'
This is the same man who argued that details of the £1m bung from Bernie Ecclestone to the Labour Party should be kept secret.
This is the man who hid details of a £360,000 loan from another minister to pay for his second home in Notting Hill.
Mandelson used, and still uses, every trick in the book to get the media to write nice things about him and to stop them telling the truth.
His own handling of the media has been crude and clumsy - even refusing to appear on Radio 5 Live for ages because I have a show on it.
You may be surprised to know, then, that in his new book he states that 'crude, clumsy handling of the media by overtly controlling and politicised press officers causes more problems.'
At first I thought the whole front page of The Guardian must be a spoof, but 1 April had long passed. The next day we learnt about Mandelson's new view on tax: 'New Labour needs the political self-confidence to make the argument for tax rises.'
Just prior to the 1997 election I was in a meeting with Mandelson, Blair, Brown and Ed Balls the Chancellor's economics adviser. A furious argument ensued where Mandelson and Blair argued that we must say that Labour would not raise taxes at all. Brown refused and Mandelson flounced out of the room. When Balls asked Blair what we were supposed to say after the election when the tax burden went up, as it inevitably would, Blair told him to wash his mouth out.
Mandelson now states: 'New Labour government mark one has been too controlling in the way it tries to run the country.' It is as if he was never there or that he never wanted to hoodwink the country into believing that taxes would never go up.
Mandelson has decided to stay in politics rather than move into PR, which was good news for the PR industry. No-one in Westminster, though least of all the Chancellor, believes a word of his recantation. It is all the more sad, then, that a serious newspaper should bother to shovel up this garbage from the Prince of Darkness and then call it a 'sustained and cogent analysis' in its leader column.