Theatre Cat and Mouse (Sheep) / Services Gate Theatre, London

The choice of Gregory Motton to represent Britain in the season of "the most exciting European playwrights writing at the moment" sets the tone for the next two months at the Gate. Here it is not the well- made play which is being sought but the vibrancy of vision. With Cat and Mouse (Sheep), Motton is in characteristically iconoclastic, strident form.

We are in a village shop somewhere in Middle England. An old woman, played by a young man with a headscarf, buys aubergines from a young woman referred to by the old man in the shop as "nephew". But the nephew, Gengis, has ambitions. He breaks his gentleman's agreement with the shop next door and embarks on a price-war that quickly puts his neighbour out of business. By the third scene, Gengis is the supreme ruler and law-maker in England.

For the first 20 minutes of the play, you enjoy feelings of shock, curiosity, amazed bursts of hilarity, bemusement, irritation, sudden clarity, confusion, more amusement - and then you are at home with the Motton genre. But you still have over an hour of the same to sit through. When the furious and adamantine block of political satire rises up, iceberg-like, from the sea of wilfully obscure wordplay, it is brilliant. The nation of shopkeepers, the hypocritical moral doublespeak, the Tuscanification of the middle- classes (it would be aubergines, not carrots the old woman buys in Nineties Britain), the female leader with all the worst of male characteristics, the isolationism of greed. But when the iceberg disappears, you are left with a monotonous, repetitive theatrical landscape unrelieved by progression, structure or suspense.

In Motton's own production with Ramin Gray, half the cast - Rudi Davies as the nephew and Tony Rohr as Uncle - are superb. They maintain an arch, mannered poise that helps us read the play and imbues it with an irreverence from within: they themselves seem on the point of cracking up from the ludicrousness of it all.

Annie Siddons's production of the Austrian playwright Elfriede Jelinek's Services is altogether more clumsy. It strains so hard to be funny that it almost completely fails. It's hard to judge the play on the basis of this contrived excess and determined vulgarity, though in fairness, the play lends itself to such treatment. In a motorway service station two horribly dressed (pink body suit, leopard-skin leotard), mature and randy hausfrau prepare for a rendezvous with, respectively, a Bear and a Moose who have answered their ad in the paper. In Cosi fan tutte style, the bourgeois, healthy-living husbands swap suits with the animals, and trick their wives into rutting with them instead. Presumably, Jelinek's intention was to lampoon our crass consumer-obsessed desire for authentic experience and truth, but those ideas are bludgeoned to death in this production.

n To 23 Feb. Booking: 0171-229 5387