David Baddiel's pre-show pronouncements don't fill one with enthusiasm. "It's a bigger laugh to do on stage," he says, "where we can swear and talk as much as we like about Frank's toilet habits. That's why I'm doing it." Ho hum.
Baddiel and Skinner Unplanned was touted as trailblazing telly when it premiered on ITV, after Skinner's multimillion-pound transfer from the Beeb last year. It featured the comic duo extemporising from a sofa: Beavis and Butthead for thirtysomethings. Now it's in the West End for a month, and the supposedly pioneering is revealed as lazy and inadequate.
The concept isn't the problem. There's a lot to be said for establishing an honest, spontaneous relationship between audience and performers - fellow improvisers Improbable Theatre, who also have a comedy background, have been fruitfully exploring this territory for years. There are rousing moments here, too, as when Skinner and Baddiel have an entire West End audience singing along to Robbie Williams's Angels (the choice of song is characteristic).
What lets Unplanned down - and threatens to derail it altogether - is its lack of ambition. Within the opening minutes of their hour-long gig, the pair are calling punters "gay" and talking about willies. Having cracked a joke about Abraham Lincoln, they apologise for overestimating the audience's intelligence. They don't make the mistake twice: "Who remembers the firemen's names on Trumpton?" asks Baddiel.
Understandably, a rowdy crowd interprets this comic barrel-scraping as a licence to join in, and duly does so. A man whose birthday it is plonks himself on the boys' leather couch and announces he works for Railtrack. Everyone boos; the volunteer "secretary", Caz from Essex, scribbles "wanker" on a blackboard. As the evening slides into office-party raucousness, Skinner and Baddiel - the latter's eyes flash with panic - seem quite incapable of reining it back.
It falls to Skinner to partly redeem an event that without him would be as appetising as the dregs of someone else's pint. His persona is twinkling and jolly. He seems positively interested in people and in the world. And he can be suddenly, effortlessly funny, piercing the fug of pub-bound blether with tangential shafts of wit. On their first night, the pair's opposing responses to foot and mouth spoke volumes. Skinner indicated the absurdity of the government's response: "Earache? Get on the bonfire!" Baddiel was sneeringly cynical: "Let's face it, those of us in London, we don't fucking care anyway." Baddiel's crime isn't that he's a lad; it's that he's desperate to be one. Swearing is his primary comic strategy (and sex, a topic he snatches at like a drowning man thrown a rope).
It all amounts to a waste of a format that might be developed in interesting directions, and of a dynamic live atmosphere. Unplanned needn't mean unimaginative or unfulfilling. But unless, like Skinner and Baddiel, you're content with ever-decreasing circles of low-brain banter, I'd unbook those tickets immediately.
Until May 12. Box office: 020-7420 0120.