Rupert Everett will star in drag in a 21st century take on the popular St Trinian’s films of the 1950s and 1960s. The actor will play the dual role of the school’s inept headmistress, Millicent Fritton, and her crooked brother, Carnaby.

Other cast members include Mischa Barton, star of The OC, Colin Firth, best-known as Darcy in the BBC’s Pride and Prejudice, and Stephen Fry, who will present a "School's Challenge" quiz show.

According to Firth's website: "The girls of St Trinian’s school pull off a great scam (involving the theft of a priceless painting) in order to pay off enormous debts and save their beloved school from closure."

Scenes for the Ealing Studios project – which is being marketed at Cannes – have already been filmed in and around London, with Everett spotted sporting a neon pink hooded tracksuit, silk headscarf and aviator-size dark glasses.

The original films, shot in the heyday of Ealing Comedies and based on cartoons by Ronald Searle, feature the over-the-top “japes” of saucy schoolgirls at an exclusive girl’s boarding school.

While the younger girls run riot, their sixth form schoolmates exploit their precocious sexuality. Smoking, drinking, gambling and violence are prevalent. The teachers are just as disreputable.

Miss Fritton – a severe-looking older woman – takes an unorthodox approach, saying: “In other schools girls are sent out quite unprepared into a merciless world, but when our girls leave here, it is the merciless world which has to be prepared.”

The double role of Miss Fritton and her bookmaker brother was first played by Alastair Sim in 1954.

Everett, 47, appeared in drag as the dying socialite Flora Goforth in an acclaimed stage production of Tennessee Williams's black comedy The Milk Train Doesn't Stop Here Anymore in 1994.

Last year, the star of My Best Friend's Wedding and The Importance of Being Earnest said he believed that coming out as gay had ruined his chances of securing major Hollywood roles.

The new St Trinian's film is expected to be released in 2008.

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