Kerry puts the fiery into Flame

Some people find Kerry Fox really rather scary. This, after all, is the girl who ground her iron heel into Ewan McGregor's face in Shallow Grave, who dressed up as a man for a dare to go drinking with John Hurt on location in the Philippines, who made a more convincing screen lipstick lesbian than the real thing - Sophie Ward - in a Joanna Trollope TV adaptation, and who reckons that she can drink even more than her Fanny & Elvis co-star, Ray Winstone. Some people would be damn right to be scared, it seems.

A throwback to those sexy cinematic strops Lauren Bacall and Glenda Jackson, the lynx-eyed Fox seems to have all that it takes to make a mega-diva. But, at the moment, the 34-year-old actress keeps a wary distance from the cult of personality, preferring to lose herself in roles as the most chameleonic performer of her generation since her remarkable, multi-award-winning debut, cast completely against type as a frizzy-haired frump, in Jane Campion's An Angel At My Table.

Plonking green-toenailed feet on the chair between us, Fox gives me a feral, white-toothed grin and waits edgily for the questions in a don't-mess-with-my-mystery manner. First on the agenda is ... er, her attitude, well on display in the latest role to exploit the quality once described by Shallow Grave director Danny Boyle as "always something blazing within her". She certainly won't need to delve too deeply into her psyche to play the tough, appealingly independent Alex in Charlotte Jones's award-winning play In Flame, a deserved hit last year at the Bush and now transferring to the West End.

There's a restlessness about Fox that suggests a tremendous drive, frustrated by the lack of work in her native New Zealand and more recently by the limitations of the British film industry that should have made her a star by now. Yet Fox is no foot-stamper, just a very blunt, to-the-point Antipodean, who now considers herself a permanent member of one of London's multi-cultural tribes after living here for six years. Recently she bought a house in West Hampstead with her gay friend Peter Gordon, who was head chef at the Sugar Club and Barley Sugar restaurants, and his partner Michael. A girl's gay friend is not just for Christmas but for life, it seems, in this new design for living, particularly if he's a fellow New Zealander.

"I'm terrible at being alone; I can't do it. And Antipodeans stick together over here: it's a Kiwi cabal. Peter and I had shared a place for six years, so it made sense to buy a house together. I feel as if I'm here permanently.

"The thing I like about London is that everybody is so different: it's just so rich and bustling. A lot of New Zealand is so dreary by contrast.

I'm aware I have an attitude; but I see myself as being honest," she adds with a shrug. "I like the way I deal with people. That's why I love the line in the play where my character tells a man that he's not the sort of person she finds attractive. It's the right thing to say, she's very direct; why spin anyone along? New Zealanders tend to avoid confrontation, but Australians have a bulldozing brashness; maybe I'm guilty of that some days.

"I lived in Australia for six years, and I was astounded by their bluntness - particularly the women - but also really impressed by it. I admired them - and I can't deny that I adopted it." Her own father once called her the bossiest and most aggressive person he had ever met.

Fox, who can take a joke against herself, lets rip with a surprisingly endearing har-har-har at the memory. "I'm learning to control and manipulate my bossiness. On holiday in Spain, the Luftwaffe general came out in me and I thought I'd lost it; everything turned me into the general."

Time to ask about her claim to have drunk Ray Winstone under the table, something that at least one industry professional thinks is impossible. "Oh yeah?" says Fox impudently in her sing-song accent. "Well, I was able to drink more than Ray on occasions; it was vodka, he was into vodka." Both Winstone and Richard Harris, her co-star in To Walk With Lions, were pussycats in Fox's company, apparently.