Britain's Power Elites: The rebirth of the ruling class By Hywel Williams

It is beginning to feel as if the Sixties never happened. With well-heeled public schoolboys back in control of the Tory party, Private Eye finds itself back where it started 40 years ago, lampooning the grouse-moor lifestyle of Alec Douglas-Home. A columnist suggested that Hugh Grant has paved the way for David Cameron by making toffs cuddly again; and suddenly they seem to be everywhere, from politics and business to TV and the arts, effortlessly reasserting their old dominance. Behind the casual informality that is now obligatory, the assumption of increasing classlessness has been decisively reversed.

It all began with Mrs Thatcher, but her quite deliberate widening of inequality - under the rhetoric of meritocracy - has been enthusiastically entrenched by New Labour's fawning subservience to the interests of the super-rich. We can all sense what is going on; there are the faint beginnings of a backlash. But we need an authoritative study which clearly lays bare the renewed concentration of power and wealth that has occurred over the last 25 years. Unfortunately, this book is not it.

Hywel Williams's model is the "heroic" American sociologist C Wright Mills, whose The Power Elite (1956) was a groundbreaking analysis of the stranglehold of corporate money in US politics. His first chapter is a solid introduction to the idea of a governing elite, taking in Plato, Calvin, postwar British mandarins and the French enarques. But then he slides into a scattergun polemic which is more angry than informative. Lengthy footnotes - one seventh of the book - suggest a great weight of erudition in reserve, but it is not deployed to make a coherent case.

Williams's central claim is that the political and professional elites which have always sought to perpetuate their own influence behind a façade of democratic accountability have been usurped by a new financial elite, whose power "is no longer seen as the remarkable and novel thing it truly is". He cannot make up his mind whether there ever was a golden age. Sometimes he suggests the vaunted integrity and pluralism of British democracy was always a myth cultivated by the elite. But, generally, his purpose is to assert that there has recently taken place an unprecedented "power grab" which "now separates Britain from any period in her history".

He is describing something real and important. The ever-widening gap between the huge salaries and even grosser bonuses creamed off by the new class of consultants, accountants and hedge-fund managers on one hand, and ordinary people doing useful jobs on the other, is not only obscene in itself. It has also corrupted the political process - as recent revelations have shown.

The cosy relationships between ministers and a succession of dodgy financiers reflect a political culture which has sold out to business, most wickedly in the ongoing scandal of PFI deals by which the public is systematically ripped off. Even party conferences are now sponsored by companies in pursuit of contracts. The new post-Thatcherite consensus politics has reverted to an 18th-century struggle for patronage and place.

The trouble is that Williams never attempts to establish who his elite, or elites, are. The word recurs as a catch-all smear on anyone with power. But there are always elites: the important thing is whether they are open or closed, permeable or self-perpetuating. Inequality alone is not the same as an elite, so long as there is social mobility.

Williams does assert that "social mobility is now lower in Britain than... in any other advanced country with the exception of the USA," and cites figures to prove it. But this aspect needs much more attention to make his case. To say that business and international finance have acquired too much power is one thing; to allege that this power is wielded by a new elite - though it may be true - is quite another. C Wright Mills would have called for more investigation and less rant.

John Campbell's 'If Love Were All: The Story of Frances Stevenson and David Lloyd George' will be published by Cape in June