The interview: Tara Fitzgerald talks to Dominic Cavendish

When she arrives, Tara Fitzgerald is looking flushed, buoyed up by deep intakes of wholesome Barnes air. She orders a mineral water, raises a bemused eyebrow at a loud mothers' meeting in the corner of the cafe and lights up, immediately recounting how she used to cadge cigarettes as a teenager. She is cheerful, ordinary. I am slightly disappointed. I was hoping for formidable, starry. In the BBC's forthcoming Anne Bronte adaptation, The Tenant of Wildfell Hall, she is brilliantly formidable. The star of the show, no question. Her pale, impassive face seems to haunt every shot, conveying bleakness and remoteness more succinctly than an isolated patch of Yorkshire Moors heather. The contrast with her current film, Brassed Off, couldn't be more extreme - or more refreshing: for all that movie's virtues (and for all its critical acclaim), its ubiquitous poster features her most blandly pleased-with-herself smile to date.

Tara Fitzgerald, 29, has had the makings of a star ever since she left drama school six years ago and walked straight into Hear My Song ("jammy I know"). But she has become known more for the men she has worked with (A-list Nineties males such as Hugh Grant, Rufus Sewell, Ralph Fiennes and, in Brassed Off, Ewan McGregor) than for any one project. In popular perception, she falls somewhere in between established British actresses like Helena Bonham-Carter and Emma Thompson and young upstarts like Kate Winslett and Minnie Driver: beautiful, but lacking clout. She attributes this partly to having avoided Hollywood: "If you go out there and star in a big movie, you become more noticed back here. So people imagine that it must be the next step, or that there is something peculiar with you if you don't go."

If she wanted to go, she could probably get on the next plane. She has a propensity for nudity that makes Greta Scacchi and Sharon Stone look coy. Hear My Song opened with her leaping, mid-coitus, from under Adrian Dunbar's Liverpudlian music-hall impresario. In the TV adaptation of Mary Wesley's The Camomile Lawn, she dumped one of her lovers in the bedroom ("You've behaved like a young man in a brothel," he retorted). In Sirens, she was the repressed wife of the repressed clergyman (Hugh Grant, natch), imagining herself naked in front of an entire congregation.

But she wants more. More challenging roles. Emotional nudity. "Liberating" is how she describes her role as Helen Graham, the woebegone heroine of The Tenant of Wildfell Hall, who flees from the abuses of her dissolute husband (Rupert Graves). "What you see," she says, puffing away, "is much more me. For a start, there's no makeup. I used to look in the mirror at five in the morning and think `Oh my god'. But you have to push those worries to one side. In a way, I'm almost more naked than when I took my clothes off, where I could rely on body makeup to act as a sort of psychological shield. The fact that there is no nudity forces people to look at the acting."

Far from leaving her exposed, her austere screen presence could revitalise her mystique. "My tendency has always been towards strong, repressive roles. This character is particularly detached." She too, she says, is detached, "slightly on the edge". She would come across as aloof on screen, were it not for her voice - baritone, honey-thick. Jonathan Kent, who directed her as Ophelia in his fast-paced Hackney Hamlet last year, believes that it marks her out from the pretty-girl crowd: "She has a sort of schizophrenia - this innocent look and also this dark-brown voice. You realise that what you see is not entirely what you get."

What you get, face to face, is a kind of inscrutable frankness. Her voice may be a wonder to listen to, but the more she talks, the more you realise how much she loves the sound of it. Her leading men have all been "wonderful". There was Ralph Fiennes, the Hackney Hamlet: "He is very poetic ... incredibly brave ... sublimely professional." Ewan McGregor, co-star of Brassed Off, is "a great pal... a buddy," and she says of Hugh Grant, with whom she also starred in the ineffectual An Englishman Who Went Up a Hill and Came Down a Mountain, that "he's funny ... hilarious." What did she think of the Divine Brown incident? "It's odd, but it completely passed me by, I was away at the time." A favourite actor, though? "You fall in love with everything about a job when you're doing it. You give yourself to it, then move on to the next thing."

This is a pattern she learned from childhood. Her formative years were nomadic: Scotland, the Bahamas, Stratford-on-Avon, six primary schools. When her Irish mother brought her, with her two sisters, to London at the age of three, they lived with her uncle and aunt - both theatre professionals. Her father, an artist, had just left them. "It's not a violin story, but I did feel like an outsider. You met people, but never got to know them very well. As a result, you'd go in very quickly, then withdraw."

When she was 11, she was told that her father had died in a car crash. At 19, she learned that he had, in fact, committed suicide. ("You found your strength on certain beliefs. When those are taken away, it all topples down and you have to start again.") Her mother, she says, compensated for his absence, but she was constantly aware of their financial circumstances. "I remember feeling quite hard-done-by. I was very materialistic as a child and I missed not having nice things. My mother drove an old banger - I was mortified every time we drove to school."

She left sixth-form college in the first year, preferring to earn money waitressing, buying "nice things", and enjoying the London club scene. "It was a relief to be able to afford what I wanted and have a good time for a change. I was quite a drop-out really. It seemed good enough for me as a teenager, but I don't really know what I would have done if I hadn't got into drama school."

It took three goes to get in. The Drama Centre finally gave her a raison d'etre and polished up her south London accent. It also helped her to push to one side the might-have-beens raised by an ectopic pregnancy, which involved the removal of a fallopian tube and an ovary, at the age of 19. Looking back, she admits that things have turned out well for her: "But you either use your luck or you don't. You have to work hard. There are no instant results, but in some way you are rewarded for what you put in."

Perhaps this explains why she takes such a remarkably cool view of the poverty in Grimethorpe, where Brassed Off was filmed. "There are different kinds of impoverishment," she says. "The people there have a very strong relationship to the land. It's like being poor in a sunny clime, you don't feel it as harshly if you're living surrounded by beauty, as you do if you're living in a city like London." So, no future Glenda Jackson. "I do very little to help the rest of the world. I'm not going to start demanding that other people do."

Tara Fitzgerald is clearly not falling over backwards to create an out- of-the-ordinary public image. "There is no room in this country for starry behaviour," she says. Helena Bonham-Carter has only to open her mouth (and suggest, say, that her career has been held back by her looks) to attract comment, but Fitzgerald opts for the safe side of obnoxious: "You can get divorced from reality in the acting world - a trip on the tube sometimes can be tremendous."

For the time being, her heart is in England and in the cottage she shares with her fiance, Dorian Healy, one of the stars of Soldier, Soldier. She bridles at the word comfy. "I don't feel comfy, I never want to feel that. I associate it with stopping, with no longer finding out things." What does she feel, then? She pauses. "Happy." And she smiles a smile that is not too pleased-with-itself and is perhaps quite endearing and heads off back home to feed Famous, her puppy.

9 `The Tenant of Wildfell Hall' starts Sun, 17 Nov, BBC 1.