Dame Helen Mirren has likened working on 'Catherine the Great' as going into a "nunnery"

Speaking to The Sunday Times' Culture magazine, she said: "When you go into this sort of work, it's like going into a nunnery, really. You just have to go into a mode of proper diet, no drink, no partying, go to bed early. I should be knackered, but actually I feel great."

Meanwhile, Helen previously admitted she thinks things have "changed substantially" for women in the film and television industry as of late.

Asked if she has noticed any changed, she said: "Hugely. In the last 10 years - or really the last three or four years - things have changed substantially. There is a pressure mounting behind a dam, and I hope that that dam is finally bursting in terms of women directors and women-led dramas. When I first did 'Prime Suspect' they were not at all sure that a female-led drama would be acceptable to the public. So that's how much things have changed since we first began 'Prime Suspect'. It's changed hugely."

And the 'Woman In Gold' star also claimed some males are "locked in a past world" and won't accept change, but admitted her statement was "generalised".

She added: "The wall will continue to be hit for some time, absolutely. But I think there is a very substantial change in attitudes. I think it's becoming embarrassing to turn someone down because they're female. The mind-set has changed.

"Unfortunately there are dinosaurs, and there are some dinosaurs that are 50 instead of 80. A lot of males over the age of 50 are locked in a past world really, and we just have to let them pass through the system and get them out the other end, if you like, for things to really change. That's a very generalised statement, so maybe I should stop right there."