“I could never get along with Cherie Blair, I found her too shrill”

And suddenly Mandelson grabbed my arm and said in a rather loud voice, “But I'm a celebrity.” There was not a hint of irony, not a hint of self-awareness, just a little groan from Mandelson. That's the thing people don't realize. I'm a celebrity.

Mandelson could be magnetic when he wanted to be. He walked very slowly and carefully, especially when entering a room or restaurant, and almost encouraged people to surround him. In all the photographs taken of him during a GQ at Isola, Oliver Peyton's short-lived postmodern trattoria in Knightsbridge, he was surrounded by the likes of Gordon Ramsay and AA Gill. And he doesn't just hold court judging by the expressions of those around him, he delivers good manna from heaven. He liked people to admire him, to look at him.

Mandelson was good at drawing attention to himself. One year, at a ski lodge party in Davos during the World Economic Forum, he wore a very attractive ski sweater. He reached up with both hands to grab an exposed beam and started doing pull-ups (he was pretty good). It had the desired effect, and the entire room, which included Rupert Murdoch, Naomi Campbell, George Osborne, Gordon Brown, Rebekah Brooks and Matthew Freud, stopped to stare, like moths around. A flame. He always reminded me a little of Shere Khan played by George Sanders in the original Disney version of The jungle Book.

Mandy was always very enthusiastic about being invited to our parties, and in the email correspondence between us, when I reread it all, many messages were about party and dinner arrangements. When were they? Can we be sure he was invited?

When he chose to be, he could also be extremely funny (he always managed to make Elton John laugh, oddly). He called me once, pretending to be panicked, and said: You're not a sex magazine, are you? Only if you want us to be, I said. Not yet, I don’t think so, he replied.

Regardless, Mandelson saw my point about his columns and got to work. I started to enjoy his writing a lot more, but he didn't necessarily improve as a person, and after a while he became a little irritable. After we separated, he published his autobiography, The third man. All I needed to know about him was contained in one of the photographs in one of the many eight-page sections of his book: he was reclining on a deck chair in someone's stately home (Relaxing ), with Sabrina Guinness and Mick Jagger. artfully arranged in the background. There he is, Peter Mandelson, finally a celebrity.

One day in June 2007, I found myself sitting with David Cameron in the back seat of his chauffeur-driven Prius as it drove through the streets of suburban west London. A by-election was approaching and Cameron was campaigning on behalf of the local candidate, visiting local greengrocers, dry cleaners and newsagents, spreading the new Tory love.

Having been Conservative leader for only two years, he did his best to convince anyone who would listen that his new breed of compassionate conservatism was the only one on the table and that all previous iterations of Conservative ideology must be banished. And so far, it seems to be doing a pretty good job. His personal ratings were high and the media was taking notice.

Around 11:30 p.m., just after Cameron quickly downed a cappuccino, his cell phone rang. Still in opposition, it was the time when his phone only rang once an hour, the time when he could call one of his assistants to ask if there had been any calls, to get answer no. This morning, the person on the other end of the line was Boris Johnson, calling at Cameron's request to discuss the Conservatives' bid for London mayor. Cameron needed someone to oppose the incumbent, Ken Livingstone, who, in the eyes of many, was still the clear favorite. Boris had been in the frame for a while, at least internally, but recently he seemed to be wavering.

Having managed to secure a safe seat in Henley, Boris wasn't sure he wanted to give it up for what many still called local government. He also wanted Cameron to beg him to do it. Cameron, who kept telling the press that standing in the election was definitely Boris's idea, was keen to persuade him to get involved. Whenever someone asked, Boris would say, “I'm definitely not running, or it would be a fantastic job, but I love what I do.”