That should not come as much of a surprise. And that is the problem with this analysis of "the hidden influence of No 10". Not much of what it describes was well hidden. Indeed, its main characteristic is the triumphant way in which it states the obvious.
Richard Wilson, Cabinet Secretary from 1998, "appreciated the importance to Tony Blair of the implementation of policy and the need for departments to work together and deliver overall policy outcomes". If Sir Richard had done the opposite, his conduct might have been worth reporting. Since he simply behaved as we all should expect a cabinet secretary to behave, it is a strange revelation for two reputable academics to make. But then, the most entertaining sections of The Powers Behind the Prime Minister are those that - whether the authors realise it or not - diminish its importance.
The conclusion includes a table setting out, along its horizontal axis, "Factors Influencing Prime Minister's [sic] Fortunes": Ideas, Circumstances, Interests... The vertical axis shows "individuals" at various stages of their premiership. Dots signify success; failure is recorded by a cross. Blair I (1997-2000) wins four dots, Major III (1995-97) scores four crosses.
This is a prime example of the silly school of political analysis. Kavanagh and Seldon even use its conclusions to show that the argument about the importance of Downing Street, the basis of their book, is pointless.
If we accept this analysis, then we should be cautious about setting too much store by a bolstered No 10 as the panacea for removing future prime-ministerial problems. Pages of The Powers Behind the Prime Minister amount to little more than office-holders' gossip about the circumstances of their appointment, and descriptions of their personal habits. Thus: "Blair had followed the Major practice of convening 'Away Days' at Chequers for the [Downing Street Policy] Unit every six months or so".
The Blair advisers are listed by name. There are many important facts to be revealed about the men and the women whom the New Labour leader has chosen to give him political advice, facts which Kavanagh and Seldon fail to reveal.
Two of them have fought elections as Social Democratic Party candidates. One, by splitting the anti-Tory vote, brought about the defeat of a sitting Labour MP. Andrew Adonis (who gives the Prime Minister guidance on education policy) is the co-author of a book that urges replacing the comprehensive system with a return to at least a measure of selection. When a No 10 political adviser is an established opponent of official government policy, the fact is worth mentioning.
The virtue of this book is that it further publicises the fact that the present incumbent of No 10 is impatient with the complications of cabinet government: the need to persuade colleagues to come to a consensus, and occasionally to accept decisions with which he disagrees.
Even then, it allows its obsession with bureaucracy to obscure the political reality of his power. Certainly, in contrast to the US President, "he has few staff, limited control over the Budget - and no White House Council of Economic Advisers". But, because the executive and the legislative are indivisible and the PM controls both, a tough incumbent of Downing Street runs an "elective dictatorship" - if he has a large majority and compliant backbenchers. The powers behind the Prime Minister always help, never hinder, his ambition.
The reviewer's book 'Blood and Fire' is published by Little, Brown