REVIEWED - THE LIBERTINE: "ALLOW me to be frank at the commencement," declares John Wilmot, second earl of Rochester as The Libertine opens. "You will not like me." And we don't, even though he's played by one of the most engaging actors in cinema today, Johnny Depp.

With long hair curling down over his shoulders, and initially resembling Marc Bolan before the make-up department applies the rot of physical excess, Depp immerses himself in the role with characteristic commitment and flair, and another of his impeccable English accents.

Adapted by Stephen Jeffreys from his own stage play, the film is more a sketch than a portrait of Rochester, a poet, court wit and favourite of King Charles II (John Malkovich) in the late 1670s, and a man debauched in his rampant hedonism. There are flickers of humour, as when Rochester declares, "In Paris, fornicating with total strangers on the street is compulsory", to which a wardrobe mistress innocently replies, "I've never been further than Epsom".

The movie is obsessed with sex, mostly in talking about it through a screenplay liberally sprinkled with vulgar epithets, and going into shock overdrive when Rochester stages an obscene play laden down with phallic symbolism - a sequence that recalls Ken Russell at his most absurdly extreme.

When Rochester falls for an actress (Samantha Morton) and grooms her to play Ophelia, the drama takes an unconvincing tender turn. Much more affecting is Rosamund Pike's portrayal of Rochester's neglected, patient wife.

The Libertine was first screened as a work in progress at the 2004 Toronto festival and then returned to the cutting room, losing along the way the bard played by Shane McGowan. It marks an inauspicious, flatly paced feature debut for Laurence Dunmore, a commercials and music video director so intent on capturing the squalor and gloom of 17th-century London that his film has an ugly, murky and grainy look throughout.