Blair 'wanted to quit in 2002'

The controversial and much-anticipated insider account goes on sale this week, but Mr Campbell insisted it would not provide a "gold mine" for opponents of Prime Minister Gordon Brown.

He said he had kept out details of Mr Blair's "pretty tense" relations with Mr Brown - who has said he will not read the book - in the interests of the Labour party and politics in general.

Initial extracts instead concentrated on some of the biggest events of the Blair years, such as the Iraq war, the Northern Ireland peace process, 9/11 and the death of Diana, Princess of Wales.

And the entry which caused the biggest stir was from July 2002 when Mr Blair is recorded to have canvassed key aides about his plans to quit as PM without fighting a third general election.

"In truth I've never really wanted to do more than two full terms," he is quoted by Mr Campbell as revealing to him at the time. "It was pretty clear to me that he had just about settled his view, that he would sometime announce it, say that he was going to stay for the full term, but not go into the election as leader."

"The big question was the same as before - does it give him an authority of sorts, or does it erode that authority, and do people just move automatically towards GB (Gordon Brown)?"

Mr Blair did eventually make a statement about his future in 2004 - but by then was ruling out a fourth term and months later did secure a third general election win.

Mr Campbell has faced criticism of his decision to go public with his diaries but said he was keen to counter untrue versions of what happened behind the scenes.

"It is an attempt to say to people: forget all the stuff you have read and you hear and the rest of it - some of it is accurate and some of it is not; this is my perspective on what it was like while I was there," he told the BBC.