Katy Brand, touring

The first time I saw Katy Brand was at the Edinburgh Fringe in 2005, where she was performing Celebrities Are Gods in a tiny, windowless basement late at night. Hers was the last show in the room, which by now was a fetid sweatbox, and only a few hardy souls had turned up. But it was a memorable evening, not only because Brand’s talent was plain to see, but also because, undaunted by the circs, she performed with the confidence of an old pro even though she was only 26.

And a trouper she was again when I saw her perform her latest show, Katy Brand’s Big Ass Tour, in what might have been similarly unpromising surroundings at the New Victoria Theatre in Woking. Not that the denizens of this fine Surrey town are sweaty or smelly, you understand, but the vast auditorium was sparsely filled and the energy level in the room felt low.

The tour is essentially a live version of Brand’s ITV2 programme of the same name. On television, of course, you have hours to do make-up and costume changes, and dozens of people helping you do them. On tour, Brand uses video inserts projected on a dinky mock-up of a TV set to entertain the audience while she is offstage, a device that's used to enterprising comedic effect.

Brand’s sketch comedy baits celebrities and spoofs pop music. She doesn’t do impressions of celebs – it’s more about guying their egos and pretensions - and her favourite targets are Kate “I’m normal” Winslet and the supremely irritating Lily Allen, whose estuary demotic belies her expensive private education. Both get a run-out here, and both remain hilariously cruel, although the Winslet joke is wearing a little thin as Brand has been doing it since at least 2005.

She opens with a Lady Gaga “composition”, all flat notes and clichéd lyrics that could come from any of her ladyship’s output. The song is not one of Brand’s best efforts and her costume nowhere near as outrageous as anything the singer might sport, but the payoff – think emperor’s clothes – is clever and subtle.

The start of a running gag about Winslet making her way to the venue - a show within a show, as it were - is the first video insert, and then a stream of “live” characters follow. Among them is a foul-mouthed, cockney Queen telling us how hopeless her family are, a 2012 teenage hopeful who wants to carry the Olympic torch - “I’m not an arsonist... any more” - and a wonderfully unreconstructed army recruiting sergeant who doesn’t really want any more women joining up because she likes to be one of the boys, but have them to herself. Her Supernanny Jo Frost, unable to pronounce the word “unacceptable”, is particularly strong.

The musical line-up includes a spot-on Mariah Carey (in which Brand shows she can belt it out, diva strength), a delicious reworking of Amy Winehouse’s "Valerie" as “Valium” and my favourite, Lily Allen, banging on at length about doing absolutely bugger-all.

Much of the material - not least the Kate Winslet and a Duffy song - is looking and sounding a bit tired. A John Terry joke in a Wag sketch was crying out to be rewritten as yet more misbehaving footballers have been in the news, and Kofi Annan hasn’t been Secretary General of the United Nations since 2006.

The comedy temperature in the room was distinctly cool at the evening’s start, but Brand again pulled off a highly entertaining show by sheer force of will. And as she appeared as herself, as it were, to take a final bow, the warmth in the room was obvious and totally deserved.

• Katy Brand is touring until 19 June