If the purpose of theatre is to entertain, stimulate and shock the senses, East ticks all the boxes.

Steven Berkoff’s dramatised observations of his early life in Stepney, simultaneously hilarious and harrowing, are not for the faint-hearted.

The language would give granny a fit of the vapours, yet Berkoff hides the blizzard of swearing in a shell of delightfully rhythmic poetry, which somehow immunises the audience.

Thirty-five years after it was written it remains one of the most unsettling, provocative, politically incorrect plays you’ll ever encounter, which is doubtless why it appealed to director Tanju Duncan.

Young drama company byMoonlight served up a supercharged version of the show at Tolworth’s cornerHOUSE arts centre.

I’d seen an earlier incarnation by the same cast in Wimbledon Theatre’s studio space in the late summer (the company also performed it at the Kingston Rose studio), and it has tightened, evolved and mutated impressively.

Its success is down to a mix of clear directing and full-on, focused acting by a gifted quintet, enhanced by the disarmingly jaunty keyboard skills of pianist and musical director Greg Harradine, at times sharing the audience’s shock like an outraged narrator, at others conspiring with the actors to shock further.

East is a string of sketches in which Berkoff’s toe-curlingly irredeemable characters have free rein to exhibit their worst traits while the audience stares wide-eyed, laughs guiltily along and gasps at the excesses.

Turan Duncan and Wayne Hughes played the young tooled-up lads, Mike and Les, re-enacting their cartoon-violence fights in balletic slow motion and discussing conquests in casually sexist asides.

Shooby Ballinger played Sylv, the raunchy girl, using her wiles to full effect to stir up the primitive urges of the young men, while lamenting the fact that hers is the more passive gender.

Richard Williams and Andy Currums played Dad and Mum –a terrifying glimpse into the future for the younger cast members if they could only see what they are destined to become.

Williams’ Alf Garnett-style racist rant at the kitchen table, summoning up the ghost of Oswald Mosley, is one of the high points of a show dotted with memorable moments.

The rhyming slang that peppers the script (it would be incomprehensible to an American) makes this a very ‘London’ play, although byMoonlight aim to take a version to Edinburgh next summer.

The mix of mime, dance and song is intoxicating, and the rhythms are so lilting they could be lifted from Shakespearean sonnets, until you stop and think about the words and shudder at the meaning.

Just as A Clockwork Orange took the gentle screen song Singing in the Rain and turned it into a soundtrack to violence, and Reservoir Dogs subverted the harmless pop song Stuck In The Middle With You, East manages to find unintended menace in cheery Cockney singalongs such as Roll Out The Barrel.

The credit for that goes to Harradine’s keyboard skills, wrenching the audience from its comfort zone of familiarity with the music.

Tanju Duncan created a challenging and unsettling evening of theatre; one not forgotten in a hurry.