Calendar Girls, Festival Theatre, Chichester

A lively, funny, heart-warming tale of an unusual group of Northern strippers – that's what The Full Monty was, and what Calendar Girls tries, in vain, to be. Even without the comparison, though, Tim Firth's play is an anecdote stretched so thin that its sentimentality and contrivance are transparent.

When a Women's Institute in Yorkshire produced a calendar showing its mature members' modesty protected only by jam jars or flowerpots, the media attention prompted a Hollywood movie. The play's manoeuvres to get the audience on side suggest the labours of a Disney operation working hard to win over an audience that frowns on artistic photography.

One method is to make the naughtiness cute. These WI ladies are overage schoolgirls, somehow compelled to take part in exercise classes and attend slide talks on vegetables. Saucy photos are a way the prankish pensioners can rebel against their stern, bossy head, who is their daughters' age. Their relaxed, earthy attitude to sex, aimed at the grey market, contrasts with the frigidity of the group's two other young women, who have wretched marriages.

If any doubts linger, there's the killer argument: cancer. The suggestion for the calendar came from the husband of a recently widowed member, and the profits went to leukaemia research. The ladies are "doing it for John", we are repeatedly told, and "John would have loved it". Worthy in real life, on the stage this is emotional blackmail and no substitute for action and character. Apart from the young neurotics, the WI members are indistinguishable salt-of-the-earth types, given to chirpy, implausible wisecracks, and the play has no raison d'être after the photoshoot halfway through (a series of tableaux staged with deft comedy by director Hamish McColl).

In the second act we are belatedly asked to become interested in the individuals, who fret, fight and make up in a half-hearted manner.

The thumping normality of Lynda Bellingham and Elaine C Smith is wearying, and Julia Hills, playing a clumsy woman, staggers about like an elephant in galoshes. But Patricia Hodge and Sian Phillips are dry and droll, and the former, as the widow, is even touching, underplaying her feelings with typical intelligence. They are not enough, however, to justify this muted hymn to female empowerment through getting your kit off.

To 27 September (01243 781 312), then touring to 13 December (www.seecalendargirls.com)