DECIDING where to sit while interviewing a star can be tricky.

Meryl Streep insists on being at an angle to you, half in profile, with the curtains partly drawn. Juliette Binoche once contrived to place me on a chair facing her in the middle of an empty room, with her back to the window so that I was facing the light and she wasn't. Anne Hathaway turns it all into a joke, as she eyes the palatial gilded chair offered to her in a Mayfair hotel.

"Oh, do I get the throne, " she laughs. "I'm not comfortable on the throne, but I'll take it."

If playing a Californian highschool girl who discovers that she's European royalty in The Princess Diaries turned her overnight into a teen pin-up at 18, it's not something she wants to be stuck with. Just as her Princess Diaries co-star Julie Andrews - the grandaunt from whom she takes over as queen of the remote principality - broke away from her own goody-goody Sound of Music persona by going topless in SOB, a 1981 adult comedy directed by her husband Blake Edwards, Hathaway too has shed her safe family entertainment image by peeling off her clothes.

Nobody noticed much at first when she bared her breasts in the indie thriller Havoc. But it was different when she played Jake Gyllenhaal's uninhibited wife Lureen Twist - a role she won ahead of Sienna Miller - in Ang Lee's Oscarwinning Brokeback Mountain.

"It's the new me, " she tells me, demurely. "Brokeback Mountain is where I said, Oh my, I can act. It's a script that I just fell in love with from the beginning. Lureen's a predator, Ang told me, and it was great to have that image in my mind. I just took it from there.

"What's nice is that in addition to me going off and trying these new things, people are giving me a chance. They aren't just writing me off, saying no, no, she can't pull it off. People seem to be intrigued."

Brokeback Mountain has been credited with changing popular perceptions about the western while bringing compassionate reality to Hollywood's treatment of homosexuality. "One of the reasons it's been effective is that that wasn't really Ang's intention. He just wanted to tell a good story. He had no interest in advancing humanity. But as a result he did just that.

"People don't like being preached to. I go to church, and that's why I go - to be made better.

But in films, I want to be entertained, although I do like if something more happens in a roundabout way."

After Brokeback Mountain, wary of being typecast this time as an indie actress, Hathaway switched direction again by playing Meryl Streep's dowdy fashion magazine assistant in the glossy big-budget romantic comedy The Devil Wears Prada, for which she was unlucky not to win an Oscar nomination as best supporting actress. Encouraged by Ang Lee she has gone from that to portraying Jane Austen in Becoming Jane, a romance - filmed in Ireland - about the spinster novelist's supposed passion for a young Irish lawyer she met before she'd written Pride and Prejudice.

Academic purists are horrified at the idea of a glamorous 24-yearold star from New Jersey playing such a quintessentially English character - and still worse, the suggestion that Austen might have succumbed to sexual desire - but 24-year-old Hathaway, who is studying English at New York University, is no slouch when it comes to literature.

She points to a letter written by Austen to her sister Cassandra in 1796 in which she refers to meeting Tom Lefroy, "a gentlemanlike, goodlooking pleasant young man".

Austen enthuses throughout the letter about "my Irish friend" and urges Cassandra to imagine "everything most profligate and shocking in the way of dancing and sitting down together". According to Austen's biographer, Claire Tomalin, from then on "she carried in her own flesh and blood, and not just gleaned from books and plays, the knowledge of her sexual vulnerability".

The nearest Hathaway's Austen gets to having sex in Becoming Jane is kissing James McAvoy's boyish Tom Lefroy.

"God, isn't it a shame, " says Hathaway, "just a kiss."

But perhaps Austen wouldn't have written the novels she did if it had been otherwise. She created in her fiction the happy ending that was denied her in her own life.

"Maybe if she'd married Tom Lefroy, she'd have written Madame Bovary, " suggests Hathaway.

Hathaway was attracted to acting as a child, watching her mother Kate McCauley singing on Broadway. "I saw her die in Evita and she came back to life in time for the applause. Wow, I thought, you get to sing and act and everybody loves you."

Although she acted at school, she didn't think of it as a profession. She wanted to be a lawyer, like her father. "But then I sat down and read one of his briefs. No way could I make a career out of that. But I still go to my dad's office. Bring him a coffee. Take him out to lunch. Give him a hug."

When she was filming in Ireland her whole family came to visit her.

"We're all Irish, " she says. "My mom's side are from Donegal and my dad's from Cork." Their links are close enough for her mother to threaten to apply for Irish citizenship if George Bush was re-elected president in 2004. "We're holding out for a Democratic victory in 2008, " says Hathaway, who campaigned on the campus for John Kerry.

"All I can say is thank goodness the midterm elections turned out the way they did. I can't say anything negative about George Bush as a person. I don't know him. But I feel his presidency has been more of a dictatorship than anything else. It was just his will and nobody else had a voice. It was one of those times democracy failed, an example of how the system can work against what I think are the best interests of everyone. Bush is making a lot of bad decisions just because he wants to be seen as the guy in charge. It's unforgivable, particularly the arrogance of thinking he could force democracy at the point of a gun."

Hathaway is actively involved in the third world, travelling to Cambodia on behalf of the documen11taryA Moment In The World, organised by Angelina Jolie. She has also been involved with her Italian property developer boyfriend Raffaello Follieri in providing medical assistance for children living in deprived countries.

"He's started his own charity, " she says.

Together they have helped vaccinate hundreds of children in Nicaragua. "The economic oppression Nicaragua has endured is different to anything I ever encountered, " she says. "You kind of expect it in Cambodia but in Nicaragua, right under our eyes, it's appalling."

A growing number of young millionaires like Follieri and Hathaway are increasingly involving themselves in humanitarian work.

"We don't want to be the generation known as the one with fingers on the mouse watching while people just died of preventive diseases and hunger and genocide that we could have stopped."

Unlike her character in The Devil Wears Prada, Hathaway admits to loving clothes but is no fashion freak: she's not afraid to put on a few pounds. Tall, dark and smartly dressed in black, she bears no resemblance to watercoloured paintings of plain Jane Austen. "Playing her was such a big leap for me to take, " she says.

"For months afterwards until people started to see it and have positive reactions I'd wake up in the middle of the night with panic attacks."

Director Garry Marshall, who launched her in The Princess Diaries, calls her "a combination of Julia Roberts, Audrey Hepburn and Judy Garland". It's a much quoted quote that amuses her.

"He also compared me to Groucho Marx because of the thick eyebrows I had in the movie, " she points out.

She likes to test herself. "It's the only way you can improve, " she says. Acting to her is like a marathon. "People run with their own time groups, " she says. "It's nice now to be running with people at the level of Meryl Streep, Heath Ledger and James McAvoy."

She found McAvoy to be "the nicest guy in the whole wide world".

One day on locations for Becoming Jane they were all sitting in the make-up room, bored.

"There was a labelling gadget so we started coming up with titles for everyone and putting them on the mirror. I'd been acting with James for two weeks at that stage so I put up a label for him and he turned very red. I'd written 'Future Legend'."

Hathaway will next play a psychologist in Passenger. "I'm helping survivors of a plane crash recover from post-traumatic stress. There are questions about how the plane went down and whether it was an accident or mechanical failure. It's kind of a conspiracy thriller."

Yet another genre change? "I'm young, " she shrugs. "I have to try things."

Becoming Jane opens on 16 March