Jonny come lightly

Jonny Lee Miller is so nervous that he would prefer to play with his glass of water than make eye contact. His hair is brown rather than blond, his demeanour withdrawn but also gruff and forthright. He is nothing like the Jonny of the popular imagination, the golden Jonny captured by the celebrity lens that followed him almost constantly in the years after Trainspotting.

The marriage to and divorce from Angelina Jolie, the relationship with Natalie Appleton, the Primrose Hill lifestyle hanging out with Jude Law - they could all have happened to someone else entirely. Miller has none of the sparkle of stardom about him at all.

He is about to open opposite Aidan Gillen and David Threlfall in Dominic Dromgoole's revival of Frank McGuinness's 1992 play Someone Who'll Watch Over Me, a three-hander inspired by the Beirut hostages which, on its original run, transferred to the West End and then to Broadway. Featuring an Irishman, an Englishman and an American (Miller) chained together in a tiny cell for an indeterminate period, the play has clear resonances for a world recently shaken by the Iraq hostage takings. But Miller is having none of this 'a play for our times' nonsense. 'You can't approach it with this big worthy banner, as something that deserves to be heard, because that would come across as pretentious. It will resonate anyway. It's that simple.'

Pretentious is not a charge you could lay on Miller. A lot of water has passed under the bridge since he became everyone's favourite junkie pin-up as Sick Boy in Danny Boyle's 1996 adaptation of Irvine Welsh's novel Trainspotting. The hype that came his way because of it was never borne out by the string of increasingly minor hits (Regeneration, Plunkett And Macleane, The Escapist) that followed, while Natural Nylon, the production company he set up with Law, Ewan McGregor and Sean Pertwee, failed to deliver on its seemingly glittering promise.

Then last year he appeared in 2004's theatrical smash hit Festen at the Almeida, which promptly transferred to the West End, although without Miller. He puts its success down to the subject matter. 'One in nine people has experienced some sort of abuse,' he says. 'If you've got a crowd of 300, it's going to strike a chord.'

He also stars in Woody Allen's current feature Melinda And Melinda. ('You don't say no to a Woody film'). He has, he admits, learned a lot over the years. 'You've got to get over yourself, not worry about consequences,' he says in a voice that is a contradictory mix of hesitant and geezerish. 'That way, you'll come out of things much better. I can do an American film that might not be Ibsen but which makes people laugh and come back and do a London play, which makes me happy.'

He is relishing the challenge of Someone Who'll Watch Over Me. 'When people are subjected to extraordinary suffering, it's amazing how it can connect them with their humanity,' he says. 'The three of us go to some dark places in order to cope and some of them are quite beautiful.' He shakes off the responsibility of portraying an experience that has been endured so publicly by people such as Kenneth Bigley, Brian Keenan and John McCarthy and believes that the greatest challenge lies in the way all three roles are so closely interconnected. 'What I do on stage has a direct bearing on what the other two do.'

He clearly loves the theatre, although he is wary of coming across as a luvvie, and at one point lays into the tendency of new plays to run without an interval. 'I'm not a fan. Chekhov designed his plays to have a 30-minute interval so that people could go out and have something to drink, talk about what they had seen, get over it, relax and then go back prepared for the second half. I hope that doesn't make me sound like a w***er,' he adds hurriedly. No chance Jonny, no chance.

Someone Who'll Watch Over Me, tonight until Jun 18, New Ambassador's Theatre, West Street WC2, Mon to Sat 7.30pm (tonight 7pm), Thu and Sat mats 2.30pm, £20 to £40. Tel: 0870 060 6627.

Nearest tube: Leicester Square