In late 1990, the Tory party treasurer Alistair McAlpine visted the not-yet-ousted Margaret Thatcher "to tell her that Britain was beginning a serious recession". Just how did the art-dealing amateur politician and building-site heir know? Well, the weekly turnover from his "antiques and curiosity business" had dropped from pounds 100,000 to a mere pounds 2,000. Moreover, "I had also noticed how quiet London was". So much for econometric models and Treasury forecasters. Forget the dismal science: all a canny PM needs is some Mayfair Mr Pooter who can stroll down Burlington Arcade and spot that trade seems a little flat today.

Political memoirs, of course, exist to service our curiosity about another kind of antique. Over the past few days, gleeful pundits have pored over the extracts fom Lord McAlpine's effort, Once a Jolly Bagman (Weidenfeld & Nicolson, pounds 20), in which the loyal Thatcherite pursues his grim vendetta against foes such as Norman Lamont, John Gummer and the Premier himself - who used, he writes, to skulk invisibly around Chequers in Good Queen Margaret's reign "pretending to be a pair of curtains". Having now read the entire volume, I can report that three-quarters of it boasts all the thrill of watching cement dry. Most of the book consists of leisurely anecdotes from the building and painting trades, prefaced by a deluxe childhood that splices elements from Betjeman and Waugh. Fancy a riveting tale of the great day when the firm of McAlpine shifted "Over 2,000 cubic yards of muck" on the Barbican site? Alistair's your man. "Being a builder can become immensely boring", he admits.

Even the missiles fired at Major's spineless "Cabinet of Chums" don't drop from a clear blue sky. It was a New Statesman interview in 1995 that first revealed McAlpine's hopes to see the Tories suffer "a good scrub with a hard brush". Compared to that image, his book's expectations of "a considerable defeat" sound a bit tame.

Yet, in other moods, McAlpine has written about political intrigue with a shrewd ferocity. His modernised pastiche of Machiavelli, The Servant, dripped with a ruthless cunning that Old Niccolo himself might have admired. Alas, he's now gone down with the English memoir malaise: name those names (well, the dead ones at least); settle old scores; and then bore the readers rigid with a tour around your cultural Hinterland - in his case, the Australian Outback.

Strangely, for a resident of Italy, McAlpine has forfeited the fine Latin virtue of succinct abstraction in favour of the Anglo-Saxon taste for tedious yarns about the chaps he used to know. A world-class cynic has declined into the usual whingeing raconteur. That seems a shame - although I'd still like to know what happened after Eartha Kitt "elected to demonstrate gymnastics on the kitchen table".

Boyd Tonkin