Ecstasy by Mike Leigh Hampstead Theatre 4/5

Mike Leigh is a master at extracting the humour and quiet desperation from bleak lives.

His famously lengthy improvisation techniques throw up the kind of finely observed, credible characters that expose other screen efforts as lazy and shallow.

Leigh’s 1979 play, set in a shabby Kilburn High Road bedsit, is a vintage display on both counts, an intense, compassionate slice of white working class life, immaculately performed in this self-directed revival by a fine ensemble cast.

It’s not always easy watching. Little happens for nigh on three hours. Little will happen for these disenfranchised builders, petrol station attendants and decorators. A world away from careers, education and property ownership, their wages stretch only to paying rent, feeding the meter and boozing away their sorrows. Even sex is overshadowed by violence and unwanted pregnancy.

Lonely Jean, a woman who expects little from life or men. swigs neat Martini and invites her oppressively macho boyfriend back for joyless sex. Her best friend, the garrulous, outspoken Dawn, has three children with barfly husband Mick, who’s always in the pub. Friend Len, who talks in platitudes, moved back home with mum when his wife ran off with someone else.

Act two sees the quartet get pissed, sentimental, singing songs and reminiscing at length about younger days and unfulfilled dreams. You can almost smell the disappointment, and the candlewick bedspread, in Alison Chitty’s cramped bedsit set, which forces everyone on top of each other. Even Mick’s larking exhortations to drink up conceal a depressing future drinking his life away.

But his and Dawn’s mutual love, and Len’s tender consideration for Jean are tiny treasures in otherwise hopeless lives. While it’s unfair to single anyone out, Sian Brooke’s final heartrending confession of Jean’s emptiness is quietly devastating, and Sinead Matthews’ hilariously sozzled Dawn is a classic Leigh comic creation.

Until April 9.