Media playback is unsupported on your device Media caption Tony Blair: ''The relationship with Gordon was very, very difficult''

Former UK Prime Minister Tony Blair has said his successor Gordon Brown could be "maddening" and accused him of lacking "emotional intelligence".

In his memoirs, he called Mr Brown a "brilliant" chancellor but claimed he put him under "relentless" pressure as he tried to take over from him as PM.

Mr Blair also revealed his "anguish" over UK deaths in the Iraq war.

Labour leadership hopeful Diane Abbott accused Mr Blair of "putting the knife" into his successor.

'Going on impossible

Mr Blair's book, released on Wednesday, gives his account for the first time of the tumultuous relationship with Mr Brown, while they were prime minister and chancellor from 1997 to 2007.

Describing one row, he said Mr Brown threatened to trigger a Labour investigation into cash-for-honours allegations if Mr Blair did not agree to drop proposals to reform the state pension.

In the book, Mr Blair described his colleague as a "strange guy" who, while he had "enormous ability", had "no instinct at the human, gut level".

He added: "Political calculation, yes. Political feelings, no. Analytical intelligence, absolutely. Emotional intelligence, zero."

But he said it would have been "well nigh impossible" to stop Mr Brown taking over 10 Downing Street, due to his power base within the party and media.

Mr Blair argued that, had he sacked or demoted the chancellor, "the party and the government would have been severely and immediately destabilised and his ascent to the office of prime minister would probably have been even faster".

But he said he did not sack him because he believed "he was the best chancellor for the country" and was "head and shoulders" above other candidates.

He said: "Was he difficult, at times maddening? Yes. But he was also strong, capable and brilliant, and those were qualities for which I never lost respect."

'Disaster'

Mr Blair also said he came to the view that "unless Gordon spelt out whether he was New Labour or something different - and defined the 'something different' - it was going to be a disaster. I knew it."

On the Iraq war, Mr Blair also insisted leaving Saddam Hussein in power would have been a "bigger risk" to security than removing him.

He acknowledged "we did not anticipate the role of al-Qaeda or Iran" in planning for the aftermath of the conflict and spoke of his "anguish" over the conflict.

ANALYSIS Norman Smith, chief political correspondent, BBC Radio 4 While attention will inevitably focus on the raw personal and political animosity between Tony Blair and Gordon Brown - detailed in these memoirs - the most important political dimension is surely Mr Blair's warning about Labour's future direction. Bluntly, Mr Blair warns that Labour risks years in the wilderness unless it returns to a New Labour agenda and that the reason it lost the last election was because it backtracked on welfare and public service reform. "It won as New Labour. It lost by ceasing to be that," he says. So who does he back to take over the party? Mr Blair doesn't say. But it's pretty clear he fears anyone but David Miliband would lead Labour to "an even more stinging defeat". The real paradox is whether the implicit backing of Mr Blair will help David Miliband's campaign or, indeed, whether the Labour Party is any longer willing to listen to its most successful election winner. Political reaction Send us your comments Commentators on autobiography

"I feel desperately sorry for them, sorry for the lives cut short, sorry for the families whose bereavement is made worse by the controversy over why their loved ones died, sorry for the utterly unfair selection that the loss should be theirs."

In the book he also said he always believed he had been "in control" of his alcohol intake but admitted he had been at the "outer limit" of units of alcohol per week, something he said helped him relax and escape the pressure.

"Stiff whisky or G&T before dinner, couple of glasses of wine or even half a bottle with it. So not excessively excessive. I had a limit. But I was aware that it had become a prop."

Mr Brown's spokesman said he would not be commenting on the book, but Labour leadership candidate Diane Abbott said: "I'm surprised Tony Blair couldn't have waited a decent interval before putting the knife into Gordon Brown. It's not helpful to the party at this point."

One Labour MP close to Mr Brown told the BBC: "It is pretty much as we expected. It's certainly difficult to say there weren't tensions between them. But it is impossible to deal with the book. Once you answer one question, there are hundreds more. But we know most of it already. Tony Blair did promise to go and he chose not to. It is inevitably a one-sided account."

The former prime minister is out of the UK on publication day, attending the opening of Middle East peace talks at the White House in Washington in his role as an envoy for the "Quartet" of the United Nations, Russia, the United States and the European Union.

You can watch Tony Blair's interview with Andrew Marr on BBC Two on Wednesday 1 September at 1900 BST.