Michelle Williams always finds a "degree of difficulty" on film sets.

The Oscar-nominated actress has taken on her biggest role to date as Marilyn Monroe in 'My Week with Marilyn', and she admits although she is always nervous, taking on this role really "stepped it up".

She told Culture magazine: "It is the most challenging role I've taken, and I think it always will be. There is a degree of difficulty that always exists for me at work, but this really stepped it up. I was nervous, of course, but I tried not to think of her as an icon.

"She most yearned to play dramatic roles, but I really rather take to her comedy - and in 'The Prince and The Showgirl' there's some work that she's never bettered."

Michelle has previously claimed she was so scared about playing the part she had to have her passport taken away in case she tried to get on a plane to escape.

She said: "I was so scared. Making this film felt like being in free fall. I think after the second day, I told them they had to take away my passport because I was a flight risk - I wanted to hop on the next train to the Alps or something and get the hell out because it was terrifying."