East: Elegy for the East End and its Energetic Waste by Steven Berkoff, directed by John Bolton, lighting by Toby Bolton. With Andre Jewson, Simon Morrison-Baldwin, Sarah-Jane St Clair, James Re and James Ballarin. La Mama at the Carlton Courthouse until April 1.

This marvellous production of East reminds you how powerful language can be in the theatre. In his first, and to my mind his best play, Steven Berkoff forged an outrageous poetry from the collision of Shakespearean rhythms and cockney slang, creating a heightened theatrical vernacular that is at once obscene, audacious, dark and beautiful.

East premiered just over 30 years ago, but Berkoff's brash originality shines as freshly as ever. Its language is reminiscent of Anthony Burgess' s A Clockwork Orange, in the film of which Berkoff acted shortly before he wrote East: there is the same extreme metaphoric pressure and kinetic energy, the same ecstatic violence. But unlike A Clockwork Orange, East is a celebration of the "energetic waste" of youth, an exuberant aria of damage and desire.

Set in London's East End in the late 1960s, the London of Berkoff's own adolescence, the play is, as he says, "a scream or a shout of pain. It is revolt. ...East could be the east side of any city where the unveneered blast off at each other in their own compounded argot as if the ordinary language of polite communication was as dead as the people who uttered it... The acting has to be loose and smacking of danger ... it must smart and whip out like a fairy's wicked lash..."

What's most striking about this language is its unabashed carnality: it is arousing, in every sense of that word, demanding the immediacy of physical response. Like his contemporaries Maria Irene Fornes and Richard Foreman, Berkoff is an auteur director, who wrote and directed his own plays with the London Theatre Group. He situates his theatre in a variety of performing traditions and techniques, including vaudeville, Brecht, Artaud and Le Coq, but the emphasis is always on the text and the actors.

The tension between writerly and performative excess and an ascetic simplicity of design makes a theatre that is at once elegant and rawly affective. Berkoff's production of Salome, which toured here many years ago, featured highly stylised and expressive performances of Oscar Wilde's heightened language. In a way, it's the obvious thing to do with such naked theatrical poetry: but the obvious is not necessarily easy. It's a question of holding one's nerve, of following the gesture through, blasting past the fear of creating mere parody or shallow pastiche towards an Artaudian possibility of revelation.

VCA head of acting John Bolton has directed a copybook production that fully exploits the talents of his young ensemble, and it's as enjoyable a production of East as you'll see. The Courthouse space is draped on three sides by black curtains, which fortuitously go a long way to solving many of the acoustic problems of this space and permit very precise, black theatre lighting. The set consists of five chairs, a piano and a table set for a meal. Toby Bolton's lighting is at once subtle and bold, creating maximum effect with a sparely chosen pallet that caresses the bodies of the actors as they emerge from or vanish into darkness.

What centrally matters in any production of Berkoff's work is the performances. In East, the play depends on a sense of explosive youthful anarchy married to a high level of actorly skill: it's essential that you can hear every word of Berkoff's thick, viscous language, that every gesture is precise and measured. The length and complexity of the monologues means that sustaining energy and focus is an almost athletic challenge. These performances are remarkably detailed, reflecting months of work (the luxury of a student production): every phrase is lovingly incarnated and articulated through the bodies of the actors, and performed with an infectious relish.

East is at once a celebration and critique of the performance of masculinity. Les (James Re) and Mike (James Ballarin), the two young thugs perpetually on the hunt for a fight or a fuck, play their parts with a swaggering machismo that is so excessive it turns into a hilarious parody of itself. Arrogant and amoral, they live for the spilling of bodily fluids, blood or sperm: the moment of ecstatic release that permits them to transcend the banality and poverty of their lives. But beneath this extremity is a corrosive isolation: "I was lonely...' says Les, "basically I think, like one is born that way, I always felt lonely as if it was something like a habit..."

Their racist, misognyist Dad (Andre Jewson) simmers in a constant brew of suppressed rage, laced with a poisonous nostalgia. The high point of Dad's life, and in Jewson's frenetic performance a high point of the night, is his memory of a march with the Fascists of Oswald Mosley, beating up the "Kikes". But it is a memory of failure - the marchers were beaten back, England was not saved for the English - and Dad's only recourse is to bully his children and his wife. Jewson is 30 years too young for the part, but makes up for that by bringing a quality of grotesque caricature to the role that emphasises the play's theatricality, its play of masks.

Against this aggressive masculinity the two women, Mum (Simon Morrison-Baldwin) and Sylv (Sarah-Jane St Clair) launch a bruised but vitally resistant femaleness. The relationship between the sexes is agonistic all the way. Sylv's potent sexuality is a weapon to goad and mock the men: "So thou, bitch," says Mike, "seeks to distress my Johnny tool with psychological war, humiliating it into surrender shrink". But for Sylv, and for Mum, it's a battle that cannot end in victory: Sylv is clear-sighted enough to understand the conventions that imprison her, even if she can't do more than rebel against them.

Mum has retreated into numbness; she no longer reacts to anything except the fantasies in her head, fed by the cliches of popular culture. Morrison-Baldwin plays her, in contrast to the heightened energies of the other performances, as a centre of unnatural calmness, stilled perhaps by Valium, no longer even reacting to her husband's unpredictable rages.

Berkoff isn't going to allow the audience the luxury of easy empathy with any of these characters: even Mum doesn't coalesce into a figure of pity, but reveals her own surprising resistances. Neither does he suggest any way out of the dilemmas the characters reveal. East is joyously amoral, leaving the audience to wrestle with its contradictory empathies and revulsions.

This production gets these emotional and aesthetic complexities just about spot on. It's an exuberant and sexy rendering of what is, in the end, a paean to life, venereal warts and all. It's rarely done here, so don't miss it.