The idea of a Charles Kennedy impersonator wasn't enthralling. Parodies rely on strong characters becoming cartoons - such as Thatcher in Spitting Image.

Kennedy seemed too middle-of-the-road.

Yet since 2001 Dave Mounfield has made a splash as his only imitator. He told how he became Kennedy via Channel 5 and a cheap ginger wig, soon finding himself on Richard and Judy and Have I Got News For You, in The Observer and being thanked by Kennedy's PA for making the real man "more fun".

His Dave Gorman-style comic narration was entertaining and an ideal warm-up for another funny act.

It never arrived. Instead we were subjected to appalling sketch-based stand-up from Brian Mitchell.

Bizarre monologues were peppered with atrocious jokes - "I'm baking in here," (brings out a baking tin from under the lecturn). "No, I'm boiling," (cue saucepan) These were set to what were supposed to be "postmodern" criticisms of his own comedy.

This was indeed postmodernism.

We were watching a comedian we knew was bad, who thought he was good but was pretending to think he was bad. If he believed it, he would have done the decent thing and left the stage, saving his charming assistant Emily from bravely battling on.

Mitchell took on the guise of an auctioneer selling his jokes. I'd be surprised if he could give them away.

With a David Brent-like self-awareness, he rambled on and people fled. A full audience haemorrhaged by a third. Mitchell dressed as a schoolteacher ridiculed for the surname "Bumer".

In an "ironic" attempt to dispel laughter, he asked his pupils to call him a different name - "Gaye" or "Chetney Ferris".

Perhaps Brighton isn't the best place for material verging on the homophobic.

There was a long conversation between Mitchell and a bottle of Matey bubble bath. Half my group left. I stayed but stopped listening.

I became convinced anyone in the room could entertain us better than the man on the stage.

Another three actors came on for the finale and arrested Mitchell for being a "comedy criminal". By God, I thought, why didn't they rescue us before?

It was a shame the show spoilt the sweet taste of Mounfield.