Within minutes of meeting Tony Blair’s press secretary Alastair Campbell for the first time, in Margaret Thatcher’s plane, he told me he was an alcoholic who had become so delusional he had been committed to a mental hospital, where he suffered recurring nightmares populated by Conservative demons.

As related in “The Blair Years” (Knopf, 757 pages, $35), Mr. Campbell rolled out the same shtick to President Bush when he visited Crawford, Texas, in April 2002:

He asked me why I wasn’t drinking and I said I was a recovering drunk. Me too, he said. I asked him how much he drank. He said two or three beers a day, a bit of wine, some bourbon. He gave up in ’86, a few months after me. I went through the kind of quantities I was drinking at the end and said they dwarfed his efforts. I said that having a breakdown and not drinking had been the best thing that ever happened to me. It was like seeing the light. But you still don’t believe in God? he asked. No I don’t.

A former tabloid political reporter who shamelessly worked from a left agenda, Mr. Campbell followed a similar career path to the character Pasha in Boris Pasternak’s “Dr. Zhivago,” played by Tom Courtenay in David Lean’s movie, a once intense idealist and good guy who overnight turns into a ruthless and hated apparatchik. Mr. Campell’s diaries from the days he ran the Downing Street press office portray an intensely loyal self-appointed “best friend” of Tony Blair who reveled in the power he wielded over his former colleagues, dispensing favors and waging vendettas with all the vengeful, partisan glee of the Conservatives he once affected to despise.

To win a ringside seat for world events, with personal access to leaders and the rare latitude granted by his employer to chat with them as equals, is a perfect gift for a talented writer. Yet Mr. Campbell rarely lifts his eyes above a tabloid grasp of what is going on. There is plenty of gossip, most of it inside baseball stuff about British Labour Party infighting, and miserably few insights.

Mr. Blair, we are led to believe, is a driven, talented, selfish, vain, insecure, thoughtless, slightly effeminate metrosexual with a taste in expensive brand name clothing which the macho Mr. Campbell found hard to stomach. April 4, 2002: “TB was wearing Nicole Farhi shoes, ludicrous looking lilac-coloured pyjama-style trousers and a blue smock. … I said he looked like Austin Powers. He said you are the second person who’s said that.”

If the book is disappointing for those who would have liked an intelligent insider’s account of how Mr. Blair’s transformed the Labour Party from a divided gang of oppositionist no hopers to an effective election winning machine, Mr. Campbell compensates with a steady stream of high class gossip.

Crawford, Texas, April 6, 2001. “[Bush] said in the early days he got really knocked by the way they took the mickey out of the way he mangled words, and it made him hesitant, like when he said infitada instead of intifada and got mauled for it. Now he had given up caring what they think and it had made him more confident. He said the truth is I have a limited vocabulary, I’m not great with words, I have to think about what I say carefully. … Barney the dog came over and [Bush] said, ‘This is my Leo [Blair’s baby son].’ I said hold on, Leo’s not a dog. Yes, he said, but Barney’s the substitute for the little boy I never had.”

January 17, 2001. “[Rupert] Murdoch was coming in for dinner and … brought [sons] James and Lachlan. … Murdoch was at one point putting the traditional very right-wing view on Israel and the Middle east peace process and James said that he was talking ‘f—ing’ nonsense.’ Murdoch said he didn’t see what the Palestinians’ problem was and James said it was that they were kicked out of their f—ing homes and had nowhere to f—ing live. Murdoch … finally said to James that he didn’t think he should talk like that in the Prime Minister’s house and James got very apologetic with TB, who said not to worry, I hear far worse all the time.”

June 26, 2001. “[Bush] said to us he thought bin Laden was dead but he daren’t say it in case bin Laden popped up again.”

Mr. Campbell is a tall, intimidating Anglicized Scot who likes to play the bagpipes. But the wailing really begins in earnest when he recounts how he finally fell from grace for, his phrase, “sexing up” what became known as “the dodgy dossier,” a British intelligence report about Saddam’s chemical weapons.

Amid a swelter of false accusations, recriminations, irresponsible BBC reporting, and the suicide of a Defense Department leaker, Mr. Campbell waged his final vendetta before leaving Downing Street, bringing down with him a director general of the BBC. The whole episode was an example of the needless hysteria, drama, and anguish which came to engulf Mr. Blair’s Downing Street and that no Labour supporter, least of all the new prime minister, Gordon Brown, will miss.