“The script captured a side of London that I hadn’t seen portrayed in a film. It was very urban, sexy and funny. The characters aren’t particularly healthy, and you watch them make mistakes again and again. It’s a comedy of errors.

“Sophie is a departure for me in that I have recently played a lot of very warm, loving women who stand by their man no matter what. Sophie is very different - she is standing by herself.”

Liam is the closest to the edge of all the characters - unable to handle Sophie; driven to suicidal despair when Hannah dumps him for a lesbian relationship; and unable even to deal on level terms with Marey, to whom he introduces himself by saying he’s useless at sex. The only thing he cares about are the collectors’-item comics which he sells for a living.

Liam (Ian Hart) tells Marey he’s useless at sex.

Liam is played by Ian Hart, the hard-working and increasingly successful young Liverpudlian actor who manages to look totally different in every film - whether as John Lennon in Backbeat; as the dedicated young teacher in Clockwork Mice (for which he won an Evening Standard Award); as the revolutionary hero of Ken Loach’s Spanish Civil War drama Land and Freedom; as Joe O’Reilly in Neil Jordan’s Michael Collins; or as the absent dad in Michael Winterbottom’s 1999 Cannes competition entry, Wonderland. Hart will next be seen in the as-yet untitled comedy which is producer Uberto Pasolini’s first film since The Full Monty; and the screen adaptation of Graham Greene’s The End of the Affair, again for Neil Jordan.

“Liam doesn’t know where he fits in with women,” says Hart. “Maybe he did once, but you have one or two bad relationships and, like they say, it’s hard to get back on the horse. By the time he meets Marey, the damage has already been done: he’s had an unrequited love life and has been chucked and chucked. “I used to live in a flat in Camden. The landlady was Greek and she didn’t speak English. I kept trying to tell her that I had got an acting job in York and I’d be away for six weeks, but when I got back she had changed the locks and put all my stuff out in the garden!

“But Camden is a great place: the canal is genius. It’s also a good place to go out when you don’t have much money - like me when I first arrived in London. And it’s great that we didn’t have to make it for the film: we just found it and adapted it.”