On Christmas Day, he's Professor Quirrell in Harry Potter And The Philosopher's Stone, BBC1's big festive film of 2004.

Ian, 40, said: 'It'll be nice. Kids will watch Harry Potter and mums will watch Sherlock Holmes.

'I won't even be watching them.

'I can't watch myself. It would ruin Christmas.

'I'd be seeing myself doing something badly, or not the way it should have been done and shouting at the TV:'You sad git.' My kids will watch harry Potter and my mum will watch Sherlock Holmes and let me know what it's like.'

By rights, Ian should beup there with Gary Oldman and Tim Roth.He's one of Britain's best actors and was breathtaking as John Lennon in Backbeat - 10 years ago.

But while others have become celebs, Ian has always been happier doing the gritty roles which sadly not as many people see.

But Ian did land one of the best roles in a Harry Potter And The Philosopher's Stone - the stuttering Professor Quirrell. 'When I went to the audition, I didn't have the faintest idea about it,' said Ian, speaking from Luxembourg where he's making a new film, Rag Tale.

'I'd never read any of the books. I went to bookshops and they gave me book two.

'I was looking through it saying: 'Where's my character? It can't be that big a part as I can't find it.' 'But luckily enough I got the job.' And Ian admitted he had fun making the big-budget movie.

'I learned how to fly,' he said. 'I loved flying around on ropes.

'It's only for a moment in the film but I was there doing it for days.'

And being in a Harry Potter film, especially the first one, will mean his cinematic immortality.

'I'll be on TV for the rest of my life,' he chuckled. 'My sister bought one of the dolls, but the kids have lost its head. And I've also got a Lego version of myself, but we can't find the head of that either.'

Harry Potter And The Philosopher's Stone, Christmas Day, BBC1, 6.05pm.