COMEDY / The copy cat: James Rampton on Rory Bremner at the Orchard Theatre, Dartford

Impressionists were once the social lepers of light entertainment, banished to colonies with names like Seaside Special and Summer Season. Rory Bremner has changed all that. Thanks to him, liking impressionists is no longer terminal to your street cred. He has brought a sharp edge to an art that used to have the cutting capacity of a blancmange in a heatwave. In the post-Bremner era, it is no longer enough for impressionists to churn out 'Ooo, Betty's interspersed with the odd 'Matron' and 'Nay, nay and thrice nay.'

As he showed at the Orchard Theatre in Dartford last week, Bremner wields voices with violence; the impressions have a point beyond making you marvel at his ear. His John Smith, in full pastor's robes, delivers a sermon from a lectern because the real John Smith exudes religious sanctimony.

Perversely, the less regalia Bremner donned, the more effective his impersonations were. If you can get a round of applause just by donning a pair of glasses and saying 'Hello' in a thick Northern Irish accent, why bother with hours in make-up to become John Cole? The most elaborate make-up job - a rapping Ian McCaskill - produced the least effective sequence. The frippery distracted from the voice.

Bremner was also occasionally undone by his own ambition. Neither David Gower nor Gyles Brandreth has a distinctive enough voice to be easily aped, and people looked at each in bewilderment when he said he was doing Jim Broadbent.

A few mildewy jokes were served up - such as, 'the President of the United States and her husband Bill' - but most of the material was fresh enough to be harvested and bagged up by Birdseye. As Prince Charles, Bremner asked, 'Are there any politically correct people in the audience tonight?' - a reference to a story that had only broken that afternoon.

The live stage also gave him the opportunity to be perhaps the first major comedian to be heckled by John Major. When 'John Smith' stumbled during his sermon, 'John Major' butted in with 'Ha bloody ha]' Other hecklers were also made to think twice with the warning: 'I can put you down as Kilroy or as Loyd Grossman.'

Watching Bremner live, you can appreciate even more keenly his ability to pluck out of his imagination one verbal idiosyncracy, and polish it until it acquires the veneer of reality. Barry Norman claims he's never even said 'and why not?', but who would believe that now? At Dartford, Bremner was proffering a suitably banal catchphrase for John Major: 'I'm still here.' What's the betting we read it a newspaper column before the month's out?

'Political' comedians can have all the appeal of David Mellor in Chelsea kit, but Bremner is a challenging questioner rather than a rat- tat-tat ranter, he is intelligent rather than in-your-face. After all, how many banner- waving 'Tories Out' stand- ups would you hear using the word 'syllogisms'?