The Oddest Couple, Theatre Royal, Stratford East, London

The oddest thing about Geoff Aymer's The Oddest Couple is how it drifts away from its strong starting point as a sharp comedy about domestic violence and the subjugation of women, and turns into a muddy showcase for a series of sketch-show characters.

It is a packed evening, with a high gag rate. The versatile Eddie Nestor and Robbie Gee rampage through the script, assuming nine different characters between them. Without so much as a change of hat and coat, the guys give life to Thelma and Iggy Norant (the lone truly rotten gag), a suburban couple in a marriage gone stale.

A parade of vividly realised characters follows. The Butu Boys, a pair of cack-handed Nigerian DJs trying to convince as LA playas, the Raga Girls in their knock-off gear, and Cornelius and Alphonse, two old West Indians with Monty Python's Yorkshiremen's comic gift for topping each other's tales of hardship. The writing and characters ache to be on television - the latter pair would make just as good a vehicle as the oldies in the Chewing the Fat offshoot, Still Game.

The performances, however, far from being televisual, are a theatrical joy. In the month in which we bid farewell to Stones in his Pockets in the West End, here is a vivid display of physical comedy to take its place. Unlike Stones, unfortunately, the excellent actors bring their considerable comic gifts to material that is often thin.

In fairness, the gags come thick and fast, an enjoyable mix of hokey old chestnuts, deconstructionalist fun and incisive wisecracks. Thelma, after a beating at the hands of the oafish Iggy, is said to have been for "an Ike Turner makeover". And Karena Johnson, 2003's Jerwood Young Director Award winner, keeps Nestor and Gee's already tight double act rattling on apace. Alas, there is nowhere of substance for the actors to rattle on to.

The meat is in the first half. At the end of the first act, one of the Raga Girls tries to teach the timid Thelma the finer points of a defiant, head-rolling, talk-to-the-hand attitude, and the belly laughs are peppered with real pathos. Sadly, this balance of writing and performing slips away in Act Two.

After the interval, the writer contrives to bring all the characters to a local talent contest. Though enjoyable knockabout fun - the audience whooped the house down - and a bravura display of physical theatre, this is where the play comes a cropper. The overall feel in the second act is of a descent into panto - with the actors even taking time out to relay the I'm a Celebrity... Get Me Out of Here! result to the house.

Any attempt to marry the Theatre Royal's two enormously popular strands of black comedy - plays and sketch shows - needs to be blended with greater subtlety if the more pushy sketch elements are not to overwhelm the story. Unfortunately, The Oddest Couple ends up as "Nine Characters in Search of a Sitcom" rather than as a comedy-drama with a punch.

To Saturday (020-8534 0310)