Close-up: Ben Whishaw

The actor braces himself for the 'Brideshead Revisited' backlash

The Ben Whishaw appreciation society has a tantalising six months ahead. First, their man is to appear in Criminal Justice, a thriller for the BBC that starts tomorrow. In it, Whishaw plays Ben Coulter, a young man whose night of sexual abandon leads him into the Kafka-esque world of the British criminal justice system. "It felt like something different for me, partly because the character is a fairly normal, average guy," he says.

He's right, too. He may wince to be described as "the tragic hero of the iPod generation", yet Whishaw has earned a reputation for playing enigmatic characters: Hamlet for Trevor Nunn in 2004, a Konstantin that owed as much to Morrissey as Chekhov and a "version" of Bob Dylan in Todd Haynes' I'm Not There, to name three.

Right now, Whishaw is in rehearsal for ...some trace of her, a National Theatre version of The Idiot that has no conventional script. And, says the actor, we should expect surprises from this autumn's film of Brideshead Revisited, in which Whishaw plays Sebastian Flyte, the part taken by Anthony Andrews (with teddy bear) in the 1981 TV series. "I haven't seen it but I loved the novel," Whishaw says. "Our version will probably upset a lot of people."

But he reserves his highest praise for film director Jane Campion, who has just filmed him in the part of John Keats for her biopic Bright Star. "She changed my life," he says . "[The role] helped me get rid of things that were blocking me. I don't know how sheknew they were there. I didn't think I would respond to Keats, but now I love him – and I love Jane."

Watch a trailer for 'Criminal Justice'

'Criminal Justice' is on BBC1 at 9pm tomorrow.