After Miss Julie, Donmar Warehouse, London

Patrick Marber has given Miss Julie an arresting and very specific English makeover. In Strindberg's 1888 classic, the aristocratic young heroine engages in a dangerous mating game with her father's valet, Jean, directly under the nose of his bride-to-be, Kristin, the cook. Marber has uprooted the drama from its Swedish midsummer night setting and relocated it in a country house outside London on the eve of Labour's historic landslide in July 1945.

After Miss Julie was premiered on television in the author's own production in 1996, the year before a rather different Labour Party achieved another sweeping electoral triumph. In Michael Grandage's mesmeric and superbly acted revival at the Donmar, the piece now comes across as an eloquent metaphor for political vict-ories that don't live up to their promise.

There is no equivalent electoral watershed in the framework of the original play. Giving the proceedings this context adds a further edge of irony, for neither Julie nor her father's chauffeur are at all psychologically equipped to adapt to the brave new post-war world.

Played by Richard Coyle as a blunt, salt-of-the-earth Yorkshireman, John enjoys flirting with the insubordination that now seems to have the backing of the ballot box. But he is no revolutionary. His ambition is to emulate his social superiors, not to live by better, alternative values. In one of many shrewd touches, Marber makes John's offstage master a Labour rather than a Tory peer, one of the kind that can only tolerate the masses in theory.

Kelly Reilly is utterly transfixing as Julie. An uppity little madam with the unreal sexiness of a nubile doll, she behaves like a child acting out an un-consciously grotesque parody of sophisticated adulthood. She also lets you see that this shrill cock-tease is a lost soul, screwed up by the combination of her mother's half-baked feminism and her father's detachment.

Reilly and Coyle brilliantly register the shifts in the balance of power between Julie and John and bring out every deviant nuance in Marber's wonderfully succinct and insinuating exchanges. "Remember your position!" she shrieks in one of their post-coital wrangles. "Which one, Madame?" he ripostes. "There were so many."

Their erotic brinkmanship is goosebump-inducing. This capricious Miss Julie is capable of drinking a health to "the workers" and the next second ordering John to kiss her shoe. Watching this pair, you feel that if social class were abolished, it would have to be reinvented for the purposes of kinky role-play during sex. Helen Baxendale brings quiet presence and authority to Christine, the fiancée, showing you a woman who uses her implacable normality as a stealthy, invincible weapon.

Repositioning the play on the brink of an era of social reform highlights the drama's fatalism. Enlightened legislation might ameliorate the conditions found in an Ibsen play such as A Doll's House, but you'd be hard put to frame laws that could bring to an end the kind of primal biological battles dramatized by Strindberg. After Miss Julie therefore strikes me as a deeply pessimistic work. It also makes for a terrific evening in the theatre. Like the original, Marber's ingenious update is at once horrible and hypnotic.