'I need a break'

"But I've been working on films back to back for the past few years and I need a break. I think I just need to take time out to get a bit more of my own life back.

"If that means I have to go to the back of the queue as far as acting is concerned, then I just have to accept that." The Pride and Prejudice beauty says of her looks: "I do think I must have a nice face because I'm completely aware my face gets me work.

"But the problem is that if you happen to be someone who people think of as pretty, you also get so many people whose business it is to comment on your looks.

"I've been to photo shoots where the photographer has told me he'd kept my legs out of shot so I don't need to worry about them - that of course makes you worry.

"Then I've had make-up artists who've told me they need to shade the top of my nose so it won't look so broken. I also got rejected for a job once because someone said I had a funny mouth.

"They are all things you start to focus on. You start off thinking you're okay, then you have to go to some event and you remember you have a weird mouth, a broken nose and horrible legs."

The actress also says her father, actor Will Knightley, used to work as a taxi driver to make ends meet.