Let's lift a pint in praise of the British sex farce! Critics may sniff, but for over half a century these staples of the West End — and beyond — have offered more than just balm to the tired businessman. Mrs. Markham and similar plays showed that underneath the prim exterior, London was a swinging place. No wonder even England's thespian aristocrats enjoy kicking up their heels in a naughty comedy — just ask Dame Joan Plowright (The Bed Before Yesterday).

More important, the genre helped define a group of truly great British playwrights — Alan Ayckbourn, Alan Bennett, Michael Frayn, Tom Stoppard, Joe Orton — who bent the traditional sex farce to darker, more intriguing ends.

Well, OK. Playwrights Ray Cooney and John Chapman are not Orton, and Move Over, Mrs. Markham is no Loot. But it is jolly good fun.

Here's the setup. Joanna and Philip Markham seem to have it all, including upward mobility (he's a publisher of children's books), good friends, a solid marriage and a snazzy flat (which is being garishly overhauled by a decorator named Alistair). Does the marriage need an overhaul, too? Joanna is beginning to wonder, as she lends the apartment to her friend Linda, who plans to use it for an extramarital tryst. What Joanna doesn't know is that Philip has given Linda's husband, Henry, the use of the place for the same purpose — and at the same time. Alistair plans to use it also, for the purpose of romancing the French maid, Sylvie.

Before it's over, identities will be mistaken, many combinations explored and several doors opened and shut.

Mrs. Markham shares the liabilities and assets common to sex farce. In the former category, the setup takes far too long, and frankly, even the denouement is hyperextended. On the other hand, Cooney and Chapman provide jokes with cheerful efficiency. If you don't laugh at one, there'll be another along in a minute.

Whatever you may think of sex farce, it's not easy to play, requiring mastery of high style at high speed, physical dexterity and an ease with the British idiom. Hedgerow's production makes a game stab at it, and often succeeds. In particular, the accents are about as good as I've heard in a local production, and, despite slender design resources, the production has a sense of the period — think Mary Quant and Carnaby Street. (A cordless telephone is a jarring anachronism, though.)

Donna Dougherty (Joanna) is nimble, leggy and charming. Zoran Kovcic (Philip), David Christoffersen (Henry) and Susan Wefel (Olive Smythe) are gifted comic actors, at home with the style. Daniel Robaire (Alistair) is energetic and winning, though his over-the-top effeminacy derails an "is he or isn't he?" subplot. The rest of the ensemble do well in smaller roles, and director Penelope Reed keeps everything fizzing.

MOVE OVER, MRS. MARKHAM Through Aug. 28, Hedgerow Theatre, 64 Rose Valley Road, Media, 610-565-4211