James McAvoy has opened up about feeling like a 'pasty Glaswegian' when playing one of his romantic lead roles.

While promoting the third season of the television version of Philip Pullman's His Dark Materials, McAvoy admitted that he hasn't spoken much to the author out of fear he would say he was not right for the part of Asriel, which he plays.

He then shared some of his experiences in dealing with how authors felt he embodied their characters, and while he would not say who, he said he had two writers tell him he wasn't their ideal choice.

The Drumchapel-born actor has starred in a number of book-to-film adaptations, including Irvine Welsh's Filth and Stephen King's It.

And when it came to playing Robbie in Atonement, the 2007 film telling the story of Ian McEwan's 2001 novel, James admitted that the author gave him some feedback about his height.

He told the Guardian: “He wasn’t disparaging. He just gave me… nothing. And I was a bit devastated.

"Then he said I was a bit small – because my character, Robbie, was meant to be this 6ft tanned Adonis, and I was a 25-year-old pasty Glaswegian who’s 5ft nothing."

He then went on to reveal that Irvine Welsh "loved" him in Filth, while Stephen King was “really nice and I didn’t know what to expect from him. I love his books and I think he’s f****** amazing.”