Sex scene: Sam Gabarski's 'Irina Palm'

In recent years, film-makers have grown increasingly interested in the sex industry, whether as a subject for feature movies or documentaries.

Paul Thomas Anderson's Boogie Nights is surely the high point of this unlikely mini-genre a sprawling, picaresque epic that revealed the camaraderie, pathos and humour as well as the squalor of the Californian porno scene in the 1970s and 1980s. There have also been such recent thrillers as Wonderland (2003), in which the main character was legendary porn star John Holmes (played by Val Kilmer) and Lukas Moodysson's grim Lilja 4-Ever. Meanwhile, British Nick Broomfield has made such documentaries as Chicken Ranch, about a Nevada brothel, and Heidi Fleiss: Hollywood Madam.

It is easy to see why the sex industry exercises such fascination. It can be the starting point for wry and irreverent comedy witness Billy Wilder's Irma La Douce, which has a wonderful performance from Shirley MacLaine in the clichd role of the kind-hearted prostitute and for grim allegories in which brothels stand for the worst excesses of modern capitalist societies.

Sam Gabarski's Irina Palm was given a very rough reception when it was released in Britain earlier this year. The consensus among critics was that it was prurient, superficial and demeaning. The premise was a little on the far-fetched side impoverished granny becomes Soho sex worker to pay for grandson's hospital treatment. The director Gabarski was a Pole born in Germany who lived in Belgium. The film was only shot in London because that was the easiest way to pull the finance together. If you're looking for authenticity, Irina Palm most certainly doesn't provide it. However, the film is still unique surely the only heartwarming family comedy in movie history set in Soho's red light district. Marianne Faithfull gives a wonderfully matter-of-fact performance as Maggie, the fiftysomething granny from a snobbish home counties village who commutes to London everyday to work in a sex club.

She sits behind a wall, giving manual relief to clients whose faces she can't see. "The first time is embarrassing but, after that, you wank for England," one of her co-workers tells her.

Irina Palm certainly isn't erotic. Maggie goes about her work with the application of a diligent farm worker milking cows. Nor can the film be said to cast any new light on the murky, exploitative world of the sex industry. The love affair between Maggie and the sex shop owner Micky (Miki Manojlovic) adds one more improbable twist to a wildly improbable movie. Nonetheless, Irina Palm is nothing if not likeable. As if taking its cue from its doughty, nimble-fingered protagonist, it wrings every last drop of humour and pathos out of its own absurd storyline. The casting of Faithfull the quintessential Sixties rock chick and former muse of Mick Jagger as the suburban granny turned sex worker adds to the disorienting nature of the film. Gabarski describes Irina Palm as "a non-politically correct, romantic black comedy" and that just about sums it up.