'I'm not Edie'

YOU'D be forgiven for recognising Sienna Miller more for her red carpet appearances and much-publicised dalliance with one Jude Law than for her acting prowess. But all that could be about to change with her hotly anticipated lead role as Andy Warhol's socialite muse Edie Sedgwick in Factory Girl.

With both Sienna and the late Edie having clearly exceeded their 15 minutes of fame, it's tempting to draw comparisons between the two whip-thin, 20-something blondes who've both made more headlines for their dress sense and public appearances than they have for their art.

But while Edie quickly embarked on a self-destructive route from glamorous 60s girl-about-town to drug addiction and death aged 28 in 1971, Sienna's steady transformation from tabloid fodder to bankable actress in 2007 is well underway. After beating Katie Holmes to the role of Edie, Sienna will next appear in the indie drama Interview, opposite Steve Buscemi, and the fantasy adventure Stardust, alongside Robert De Niro and Michelle Pfeiffer.

''It was very difficult to feel what (Edie) felt,'' Sienna says of Edie's excessive and ultimately tragic life. ''I've never been sexually abused, I do not have a problem with drugs, and it's really hard to feel that pain if you've had a privileged upbringing like I have had. I'm genuinely a happy person and she was really tortured.''

And, despite their shared experiences of life in the spotlight, Sienna is keen to dismiss any personal interest in her own fully fledged celebrity status.

''I don't read all the stuff, I don't keep it, and I don't cut it out or save it or look at it or stick it in scrapbooks. If I were the type who'd be reading all about myself, I'd be sick of me,'' she says, adding that for Edie, fame itself held much more appeal.

''She wasn't famous like fame exists today. There weren't paparazzi and there wasn't the internet. It was on a much smaller scale and I think she kind of revelled in that attention. They all did - and admitted it - there was no shame in that.

''But, for me, there was just so much more to her than the celebrity thing and her wanting to be famous... She was kind of a performance artist and she had a magnetism that Marilyn Monroe had or Audrey Hepburn had, but she destroyed herself.''

Describing Edie's enduring appeal, Sienna adds: ''She was really only in the spotlight for only two years and yet she's managing still to affect my generation today. There's something really extraordinary about someone who manages to be that timeless.''

Two of Edie's major relationships are covered in the film - her close but troubled friendship with the droll and manipulative Warhol, played by Guy Pearce, and her brief but intense romance with Hayden Christensen's musician, Billy Quinn.

The latter raised eyebrows not only for Hayden's uncannily Bob Dylan-like demeanour, which resulted in the real Bob Dylan's lawyers being alerted to the film, but also for the pair's sizzling sex scene.

''George (Hickenlooper, the director) has an amazing ability to create an environment that's very safe and very trusting so you feel that you have the ability to go as far as you want to go,'' Sienna says of her experiences on set.

''He just sort of made me feel protected and reassured and comforted and encouraged constantly. And it really helped to be supported like that because it makes you want to do well for that person,'' she adds, in part explaining why she chose to shed the usual cover-ups for her risque, fully nude love scene.

In a bid to recreate the close bond between Edie and Andy, she also developed a rather unorthodox way of working with Guy.

''He'd call me up from Australia and I'd be in London and he'd go, 'Edie, its Andy', and we'd have these funny chats,'' she laughs.

But she denies reports that the pair would sneak off the set and wreak havoc out on the town still in character as the flamboyant pair.

''We had one evening when we were rehearsing in a hotel room and I think I put on a bit of black make-up and a couple of eyebrows. We were gong to go out and we lost our nerve,'' Sienna recalls.

She didn't, however, lose her nerve when it came to ''channelling Edie one last time'' after the New York premiere of the film, creating a media frenzy by appearing at the after party in Edie's signature big-knickers-over-tights ensemble and partying into the wee hours with the likes of P Diddy.

Explaining the much talked about look, she says, ''Edie used to do this jazz ballet. That was her exercise, so every day she'd put on her tights and her leotard and she'd dance around her apartment and that's how she kept trim. She was too lazy to change so she'd put a big coat on over that and go out, and everyone started to copy this look. So, it was a totally inadvertent look that caught on.''

* Factory Girl opens in cinemas tomorrow