Billie On Fanny Price

Billie Piper as Fanny Price in Mansfield Park (18 March, ITV1)

Billie Piper looks - and admits to being - tired. This is hardly surprising - she is currently in the throes of an extended West End theatre run, she has a matinee to get to after the RT shoot and an evening performance later on.

And after that, no doubt, there'll be the usual paparazzi dodgems for her and her co-star and boyfriend Laurence Fox (no, they're not engaged; no, she's not pregnant - can we move on?)

But Billie says she's happiest when busy: "I like charging around. I'm quite comfortable doing lots of different things, otherwise I get a bit frustrated." One of the things she says she has learnt playing Fanny Price, the redoubtable heroine of Austen's Mansfield Park, is that life in the early 19th-century wouldn't have suited her one bit.

"You realise the pace of life was so slow - everything takes so much longer. Our natural pace these days is so quick. If you wanted to travel anywhere it would take you two days. If you wanted to write to people, the same. Everyone would walk slower, just simple things like that."

Billie says that as a result, she finds period dramas can often be a little plodding. "I've always had an issue with period dramas. I love the language but sometimes it's just a bit too slow or stuffy and sometimes, frankly, it's a bit boring. That's my experience."

This adaptation of Mansfield Park, she says, will offer just a little more pizzazz. Clicking her fingers to give an idea of what she means, she says, "This one moves like that and it feels very real. It's a real family with real dynamics."

One of the things that Billie has learnt is that life wasn't just slower: it was harder too.

"It would have been a nightmare to have been a young woman then. They must have had stomach ulcers from having their internal organs squished up inside them, and women didn't really get to say anything - they just had to get on with it and shut the f**k up."

As, indeed, did Billie, when it came to wearing period dress. "I had 12-hour days in this thing," she says. "Sometimes they'd loosen you off for lunch, but basically you were tied in to it at the beginning of the day and then you'd have to negotiate everything - when you pee'd, what you consumed. I started drinking isotonic drinks - they rehydrate you but you don't have to go to the loo."

And, though it pains us to ask, what happens when you do? "I've got a technique. I straddle the loo, I sit facing the wall and let my dresses fall behind me."

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