A slice of Sweeney Todd and a dollop of Alfred Jarry, seasoned with Titus Andronicus: such are the ingredients of Lucy Kirkwood's grisly new dystopian comedy. It's a vivid, even lurid, work that at its best rings with nasty, maniacal laughter and at its worst is mired in confusion. Even the most eye-catching shock tactics lose their potency when repeated too often and, despite its off-kilter imaginative flair, Kirkwood's play is seriously overextended.

Josie Rourke's exuberant production, given a proscenium-arch staging in a reconfigured Bush, sometimes struggles to maintain the hectic pace it sets itself, but it delivers with brio a piece that is part strong meat, part bloody mess.

It's the late 21st century and Britain is in chaos. Thanks to global warming, Scotland is separated from England by Hadrian's Channel. There is rioting in the streets and the punishment for being caught without the right papers is horrific. In London floods have been allowed to cover the working-class areas while more salubrious ones are saved.

That measure has driven Saul, a sadistic butcher and ardent Little Englander, whose name is a sly biblical reference, out of his Barking premises and up to Bradford. Stock being hard to come by, it's often hapless members of the United Kingdom rather than the animal kingdom that end up on Saul's block. And it's in his shop, which he runs with his much-abused wife, Vanessa, that he encounters Perchik, a dissident Scottish artist on the run from the authorities. Saul recruits the newcomer as his assistant and a gristly love triangle soon develops.

Kirkwood potently suggests a future world out of joint. Life's essential elements — water, air, earth, fire — have become treacherous. Britain is a ticking bomb of social unrest. And Saul's shop, which he fondly calls his Empire, is a flimsy tinderbox, particularly at risk thanks to Vanessa's pyromaniac tendencies. But if the playwright's freewheeling absurdism is rich in theatrical flourish, her pessimism is tougher to stomach. Her point seems to be that resistance to change will result in meltdown, but she implies that, beyond the threshold of Saul's mini-dictatorship, lies an equally savage world, hinting at a moral panic that verges on the reactionary.

Still, Rourke's cast plunge into Kirkwood's gore-soaked vision with relish and come up with toothsome performances. Sheridan Smith's Vanessa is a particular delight: sweet, sexy and hiding a dangerously sharp intellect beneath a deliciously daffy manner. She is matched by Jamie Foreman's Saul, a thuggish, creepy and ultimately rather pathetic bully, and Bryan Dick's bright-eyed Perchik, whose idealism is so easily eroded by selfishness and greed. Together they cook up a storm; Kirkwood's play, though, doesn't quite satisfy.

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