Tony Blair's office has just released the first extracts from his memoirs online and the selection includes a fascinating account of why Blair refused to sack or demote Gordon Brown.

Blair's explanation is a mixture of the pragmatic and the principled. He argues that sacking Brown as chancellor would have severely "destabilised" the government and that his ascent to the office of prime minister "would probably have been even faster" (that "even faster" suggests that Blair still feels his time in Downing Street was unfairly curtailed).

However, Blair goes on to say that he genuinely believed Brown "was the best chancellor for the country", describing him as being "head and shoulders above the others".

He writes:

If I had decided he really was unfit to remain as chancellor I would have dismissed him, even if it had hastened my own dismissal. My failure to do so was not a lack of courage. Nor was it simply about managing a complex situation. It was because I believed, despite it all, despite my own feelings at times, that he was the best chancellor for the country.

He adds:

Later, when I ran through possible replacements, I still bumped up against the same uncomfortable but -- I thought -- incontrovertible -- reality. He was head and shoulders above the others. Only towards the very end did the thoroughgoing New Labour people start to emerge who had sufficient seniority and experience to have taken his place.

The extract concludes, however, with Blair employing a version of Lyndon B Johnson's adage that "it's better to have them inside the tent pissing out than outside pissing in".

He writes:

I came to the conclusion that having him inside and constrained was better than outside and let loose or, worse, becoming the figurehead of a far more damaging force well to the left.

Then there's an honest and sincere tribute to Brown's strengths:

So 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.

Yet there's a rather more damning verdict on Brown's own time as prime minister:

Political calculation, yes. Political feelings, no. Analytical intelligence, absolutely. Emotional intelligence, zero.