Jerwood Downstairs: Jerusalem

It's rare to see England's green and pleasant land onstage at London's urbane left-wing powerhouse, the Royal Court. But the countryside - or the ancient fresh air and freedoms thereof - is the stamping ground for visionary radicalism these days. And Jez Butterworth's 'Jerusalem' is the rarest of beasts: a state-of-the-nation play which is a pastoral comedy; an edgy piece of new writing manned by a big and mostly magnificent cast; and a polemic which, despite weighing in at three hours and 20 minutes, is hilarious and/or gripping throughout.

Mark Rylance is hypnotic as Rooster Johnny Byron - dealer, woodland caravan dweller, bane of Kennet and Avon Council and Lord of Misrule to the local teens. This weirdly noble ne'er-do-well is the dark heart of Butterworth's play, which would otherwise be a comically accented slice of small-time rural life, as rambling and vivid as a two-day whizz and pills bender in the greenwoods (Byron and his merry gang's way of celebrating St George's day). 'Jerusalem' is honest about the despair that inspires these revels. But it has an acute poetic sympathy for their brain-expanding visionary appeal - especially if you're in a job where you slaughter 200 cows every day before lunch.

Rylance's Byron doesn't do much apart from gulp cocktails of vodka, whizz and a freshly laid egg for breakfast, but he leads a peasant's revolt of the mind in a land increasingly dominated by the hypocritical regulations of the New Estate and the petty council officials who are determined to evict him. In Rylance's hands, this limping ex-daredevil, whose raggle taggle followers call him 'gypo' but still talk about the days when he tried to jump Stonehenge, comes over as a shaman in the shadow of Swindon: a teller of tall stories who's as stooped and uncannily powerful as a standing stone.

Director Ian Rickson also gets a lot out of the supporting cast of neglected teenage girls and drippy dropouts: Tom Brooke is a treat as wide-eyed would-be emigré Lee Piper and Mackenzie Crook slouches his way into Byron's sadsack hanger-on, Ginger. This is a production which you will find very hard to evict from your imagination.