This rates very high amongst the endless pages of political memoirs produced in recent months…..

Taking Machiavelli first, Powell marshals voices from Napoleon to Isaiah Berlin to remind us what an extraordinary work Machiavelli’s The Prince is. It grapples with the political arts in states made up of real people, as opposed to peddling high principles for idealised citizens as other philosophers do. “Machiavellian”, Powell explains, need not always mean double-dealing cruelty, for there are times when straight-talking mercy is, in the New Labour phrase, “what works” best in power play.

At home, Powell argues Blair bequeathed a high-quality mixed economy in public services that will endure as the “Butskellist” settlement when the 1950s Conservatives accepted Attlee’s reforms. With vast cuts looming, however, this seems naive. Dissatisfaction with the total resourcing available for education, social care and the rest of it will soon overwhelm arguments about the merits of foundation hospitals or academy schools.

Powell, whom Peter Mandelson dubbed Jeeves, echoes his master’s recent identification of Freedom of Information and the hunting ban as his great blunders. On the first, Powell makes a more reasoned argument than his boss – about the confused job spec of the information commissioner – for the arch-insider’s perspective.

If Powell falters in salvaging two reputations, he is persuasive in shredding a third – that of Gordon Brown. There are some tribal judgments: Blair’s courting of Murdoch was shrewd, whereas Brown should have “saved his dignity” with Paul Dacre. There is also some hammed-up history, with Brown’s aide Ed Balls likened to “Quintus Fabius, who fell under the influence of the tyrant Appius”.

But Powell is more devastating when he calmly tells tales about the neighbour from hell: how Brown would blame Blair for Cameron’s rise, question his Christianity and demand that he “stop” journalists writing mean things. The boss, however, was not psychologically capable of a Machiavellian response, and there is a rare Blairite admission that Tony had indeed “given Gordon to understand” that he would soon take over. When Powell asked Blair why he wasted so long talking to someone who makes his life miserable, Blair asks whether his top aide has ever been “in love”.

Blair himself has told most of the best stories, but Powell adds colour and insight. His endearing inclusion of personally unflattering stories, such as his demand for a special red box with “chief of staff” emblazoned on it, lend the book credibility. He has an eye for droll detail, recalling being barred from a royal barbeque because of fears that his unmarried relationship would set Prince Charles a bad example, and recounting security blowing up a box of fudge that Charles had sent to Tony.

So there are several good reasons to pick up this book, even if you are one of those idealists whose political interests go beyond “how to acquire a princedom and how to hang on to it”. That was Machiavelli’s interest, and Powell leaves me wondering whether it was really Blair’s too.