TELEVISION / Failing to test the mettle of the Iron Lady

THERE WAS one fine moment in Nick Broomfield's Tracking Down Margaret (C4), a disappointing film from a director who has a reputation for transmuting failure into gold. It occurred when Broomfield was staking out Flood Street, Mrs Thatcher's old Chelsea address, in the hope of finding someone who might be prepared to talk about her. A spry old dame (maybe even a spry old Dame, given the cut-glass accent) walked by and confessed to having rescued the prime minister's old lavatory from a skip when Mrs T had the builders in.

'They were very ordinary white things,' she said. 'She was very economical with her bathroom fittings, she didn't have anything chi-chi at all. No, no.' The loo now occupies pride of place in the corner of her drawing-room, where Broomfield's camera eventually tracked it down under a profusion of greenery. The plaque on the lid reads: 'Prime Minister Margaret Thatcher sat here 1967-1979'.

This was as close as Broomfield got to the inner life of the Leaderene, barring a few Medusa stares over the shoulders of press men and aides. Theoretically this didn't really matter, as Broomfield's stock-in-trade has long been a studied incompetence. His films set out to look as if they have been made by impoverished film students with a deficient sense of irony - establishing shots are taken off postcards, important telephone calls are made from public call-boxes (the noisier the better) and Broomfield himself wields the sound-boom like a martial arts weapon, ensuring that it is in shot rather more often than his notional subject.

He first discovered the comic fecundity of this method while making a film called Driving Me Crazy, initially a straightforward attempt to record the gestation of a multi-cultural showbiz extravaganza. When things began to go wrong with the show, Broomfield decided to stop worrying - and irritated the oyster into producing a pearl. The result was a Tatiesque comedy of errors, a funny, shrewd essay on the theatrical fetish of professionalism. He pulled it off again with The Leader, His Driver and the Driver's Wife, a rambling account of an attempt to interview Eugene Terreblanche, in which the blustering Boer's appetite for attention vied with his rage at Broomfield's blundering - you could see his shame at being pursued by such an idiot and having no other camera to turn to. In one memorable scene Broomfield even provoked Terreblanche into death threats by racing alongside his car to secure a shot.

There was a very similar scene in Tracking Down Margaret, in which he persuaded a bemused taxi-driver to cruise alongside Margaret's limo and then hammered on the window in an attempt to attract her attention. But the repetition of method and the difference in the result were telling; the charm of confession - so powerful in the early films, when Broomfield seduced you with his doggy dejection - can't be endlessly repeated without fading. You were reminded too, by this diminished echo, that his best films have emerged from the collision of two incompetences - a faux-naf film crew revealed the false gravity of Terreblanche in a way that smoother operators couldn't have achieved. Many documentarists bring their subjects up to scratch - Broomfield pretended to be too dumb to do that and achieved a different truth.

Against Mrs Thatcher's gauleiters, though, he never stood a chance. They were simply too canny to lose their tempers and too efficient at blocking his way - instead of provoking wild lunges and swats the wasp just buzzed impotently against the glass, unable to get near enough to sting.