A new play by Willy Russell is a big event in Liverpool and the Everyman, its future uncertain after the abolition of the Merseyside County Council, is packed to the gills for a bravura, pulsating comic and inventive solo performance by Noreen Kershaw as Russell's Shirley Valentine, a 42-year-old mother and housewife who packs her bags and heads for the sun. The note in the kitchen will read: "gone to Greece, back in two weeks."

Shirley is discovered preparing dinner, sipping a glass of wine and addressing her scabrously scouse stream of semi-consciousness to the wall. Beyond which lies Life. The dramatic conceit consists in the overheard musings of an unfulfilled woman, but Russell and Kershaw embrace the audience in this wonderful atmospheric three-sided auditorium so that we become not just the confidential listener, but the responsive community Shirley does not have at home.

It is a simple and effective idea, and it works very well. Husband Joe is no source of comfort; sex for him is an over-rated pastime, like going to Sainsbury's, lots of pushing and shoving and not getting what you wanted at the end of it. Joe gets culture shock going to Chester. Daughter Jane once received an autograph - and breakfast - from Henry Adrian (good local joke); she was a feminist the moment she came home and found here husband in bed with the milkman.

That gives an idea of the script's flavour, but does scant justice to Russell's ability to build his laughter into both character revelation and a structural uniformity. At some stage I assume director Glenn Walford will tighten up the second act. When Shirley discovers the clitoral orgasm courtesy of the considerate Costa ("He kissed my stretch marks"), she takes off on a rather over-extended, dangerously maudlin passage about the terrible weight of unused life.

But the performance is compelling, Miss Kershaw opening up like a bank of spring flowers. Joe has heard about the affair and is on his way, convinced that it is all down to "the bleeding change of life." The profound and perennial point of the comedy is the problem we seem to have contemplating the idea of a woman alone - in a pub, on a beach, in a restaurant. This is what Shirley learns to combat as she unravels her own sexual and social identity - in the format of a one-woman show.

Like Educating Rita, though, this is a genuine play. Rita I was less keen on than many other Russell pieces. The confessional device of the receptive lecturer cluttered the emergence of Rita; the playwright, in a sense, here writes a companion piece replacing the lecturer with us. This gives the event a much firmer purpose and more dramatic dynamic.

The play is not only funny, it is also moving. Russell, like all the best folk artists, holds up familiar aspects of life for inspection and enjoyment by an audience he knows inside out. He is an instinctive feminist --nothing to do with metropolitan fringe theatre or vegetarianism - and his work often, as here, gains richness from exposing Liverpudlian flippancy, chauvinism and defensive smart-alecking to a radical desire for people to improve their lives and see themselves with more dignity. This, in the end, is what Shirley Valentine achieves. The notable design by Claire Lyth transports us and Shirley from her brick and pine open plan kitchen to an idyllic rocky beach and the reality of romance.

LIVERPOOL ECHO