Carey Mulligan has revealed that she and Michael Fassbender tried not to become friends while working together on Shame.
The An Education star, who lost out to Olivia Colman for the British Actress of The Year at the London Critics' Circle awards, and Fassbender play a brother and sister at loggerheads in Steve McQueen's dark drama about sex addiction.
Carey said: "Michael and I decided to not become friends quite intentionally, because our characters were quite madly vicious towards each other.
"So we didn't spend any time together. I know him now a little bit, but not through the film-making.
"We just didn't socialise outside and when we were at work we were very serious."
Fassbender was named British Actor of the Year for his work in Shame and A Dangerous Method.
The Irish actor said it was an honour to receive an award from the critics who "keep us on our toes".
He added: "There's a passion obviously there within the critics. They have to watch a huge amount of films.
"The films that they've chosen are all so diverse and you can see different flavours and tastes there and it's a big honour.
"I'm very humbled, especially the company that I was in as well. It's very special."