Hanging up her corset again, Kate Winslet is starring in a powerful new film, and should be perfecting her Oscar speech, says GARTH PEARCE ©

Kate Winslet with Harvey Keitel in Holy Smoke

If she lived in wartime, Kate Winslet would probably be known as Our Katie. She is beautiful, but does not threaten men or make women jealous. She is also British to the core and says and does things the way we think things should be said and done. When offered a queen's ransom by magazines for the inside story of her wedding to assistant director Jim Threapleton, she rejected every penny and went ahead in her local church, with a reception of family and genuine friends at a country pub. When fashion editors made sneering remarks about her healthy figure, she defiantly declared that she would never diet again. At 23, this is a woman who knows how to stick up two fingers without lifting a hand.

But her sheer audacity has captivated Hollywood, and it is about to do so again. Having given her an Oscar nomination for Sense and Sensibility three years ago and another for Titanic last year, it looks set to make her a winner at last for a compelling performance in a new film, Holy Smoke. It is by director Jane Campion, who manages to split views of critics on her skill. Was her film The Piano, which won Holly Hunter an Oscar for Best Actress in 1993, an artistic masterpiece or a bum-numbing two hours of old tripe? Did she entice Nicole Kidman to give one of her best performances in The Portrait of a Lady, or manage to make her look as if she was dying on her feet? Whatever the final verdict on the film itself, one thing is already clear: Winslet's performance is the best on screen from a woman this year.

She plays an irritating Australian girl, Ruth, who is entrapped by a religious cult in India. Her blue-collar parents are horrified and employ a bizarre black-clad American called PJ (Harvey Keitel), who boasts 180 successes so far in bringing back such brainwashed victims. He succeeds, after pretending that her father is dying. Then the real work begins in the Australian outback: getting Ruth to cut her mental and spiritual ties with her religious mentor.

But who is converting whom? Much of the film is dominated by an ever-changing relationship between the characters of the initially confident Keitel and the insecure Winslet; she delivers one jolting scene, standing naked in the desert, urinating in front of him as if all her defences have been broken. His self-assurance, however, is slowly and eventually eroded and hers begins to be asserted. By the time she instructs him how to make love to her - leaving nothing to the imagination - it is she who is in charge. There is no clear message, apart from the fact that Winslet's Ruth goes through a powerful transformation to cure herself of dependence on both religion and men.

This is not going to take her on a tidal wave of adulation, like Titanic. But whereas the blockbuster film did not quite deliver her an Oscar, the seasoned marketeer Harvey Weinstein, chairman of Miramax, has spent this week at the Venice film festival renegotiating dates and times of release for Holy Smoke, to help secure Winslet the big prize. The film was originally set for a British release on October 15, followed by the United States a week later. While Winslet has been making headlines by sporting a quirky new hairstyle for the film's premiere, Weinstein has now been granted at least an extra month to build up a campaign in America - making sure it is released before the Christmas deadline for Oscar contenders. That pushes the British release back to the new year. Given his record, following seven Oscars for Shakespeare in Love at the Academy Awards in March, including one as Best Actress for Gwyneth Paltrow, anything is possible.

Winslet herself, who spent four frantic months filming last summer between Australia and India, is more than ready for the battle. "I really believe in the film," she says. "After Titanic, I felt nothing would be more challenging. But in this there were no special effects or computer graphics to fall back on. I just had to fill every moment and be Ruth, a girl I did not particularly like. She makes this sleazy old man, PJ, finally realise he is a sleazy old man. You start the movie by thinking she is crazy and f****ed up. But she has the ability to turn things around, even on her family members, and make them reassess their life." Of her own Oscar chances, she is circumspect: "It is too soon and I am too close to the whole thing to judge whether I'm any good."

She displays no such uncertainty about her most controversial scene: "I look at myself, standing naked, weeing and . . . well, f***, what was I thinking about?" she says. "I had a contraption attached to the back of my hair, a wire ran down my back and there was a saline drip with a bit of food colouring in it. I had to wedge this pipe in the appropriate place and squeeze. I worked very hard to make sure I was in shape. I did not want to lose weight, but just look fit. So I rented an exercise bike and some weights." On her emaciated-looking co-star, now approaching 60, she reports: "Harvey loves his food, but decided that he wanted to be very thin. So he bought a treadmill, weights, trampoline - the lot - and ate health food which looked like gravel. He kept on saying: 'I can't wait until the end of this movie so I can eat again.' "

On her sex scenes, she is equally straightforward: "Some of that stuff is quite embarrassing on set, standing there saying don't do this, do that," she says. "I am quite uninhibited, but there is a limit." There is also a scene in which she gets drunk at a dance and is discovered, partially naked, being pawed by two men: "I really was drunk for that one," she says. "I blame Rufus Sewell. I had seen him doing a really convincing drunken scene with Catherine McCormack in The Honest Courtesan, so I phoned him and asked how he did it.

"He said: 'I got completely plastered.' I said: 'I cannot believe it. That is so unprofessional.' But he said: 'It's the best way.' So when we got to the scene, at night, I asked one of the assistant directors to get me a quarter bottle of vodka. I went through the lot and got very floppy. I had been off alcohol for 10 weeks, as part of my fitness drive, so it hit me even harder. At one point, I could not even walk or remember my lines. But I drank some water and by the time I had to do the scene, it felt perfect."

One of the joys of talking to Kate Winslet is that she chats and chats and chats. Apart from one personal anecdote, which she asked to be off the record, she gives a most forthright view of the craziness of filming. "I hardly got any sleep," she says. "I wanted to speak to Jim, who was working on The Mummy in Morocco, every day. There were no telephones in the Australian desert, so it meant renting a mobile the size of a laptop, driving for an hour from our base in a tiny town called Hawker and speaking to him during his lunchtime, which was my two o'clock in the morning. We're on the phone all the time. I've not seen him since 9.30 this morning [it is now 4.30pm] and we've spoken five times already." As if on cue, her mobile rings. It's Jim.

She would talk to him and about him until long after the cows come home. But since there have been many second-hand reports about how she met and married her 25-year-old husband, she asks to have the record put straight. They met on location in Morocco in August 1997 while she filmed Hideous Kinky, released earlier this year. He was third assistant director on this small-budget film; she was still relatively unknown, since Titanic was yet to be released. "We fell in love right away," she says. "I was doing the film for myself, to have a good time, to work with the two young girl actresses and to get a suntan. I did not need complications. Then, two weeks into the shoot, this beautiful thing arrives. I step outside a car, see him, and say: 'F***, f***, f***!' I knew that something major was going to happen very quickly. On the first day of him being on set, he was controlling one of the little girls and I was with the other. We were both chatting away and found it was the easiest conversation we've ever had with anybody. Ever. A few weeks after that, it was all happening between us."

About their wedding - on November 22 last year - she admits she was tempted by the huge fees offered by both Hello! and OK! magazines: "We thought, for one moment, about giving half to Jim's parents and half to mine," she says. "But it is the most private, personal day of your life, and I will do it only once. And I thought: no bloody way. All my friends will be under the table, drunk. Us, too, probably. So we sent out invitations for the wrong day, in case any went astray, then phoned everyone to give them the real date. We did not give them a venue, just told them to meet at Victoria coach station at 1pm and get on a yellow coach with a green stripe. We put champagne on the coach."

This particular magical mystery tour ended, via the church, at a pub in Oxfordshire, a few miles from Kate's family home in Reading, with the lone star guest being friend Emma Thompson and her actor boyfriend, Greg Wise. "It was not at all showbizzy. We had good food, an Irish fiddle band, beer kegs, mulled wine, fireworks and big drums of veg soup and chunks of bread to finish off at 11 o'clock."

She's not been apart from her husband since marriage, choosing her latest film, Quills, based on the imprisonment of the Marquis de Sade and co-starring Geoffrey Rush and Michael Caine, so she could travel back and forth to Pinewood Studios each day from home. "I am so scared to answer the question about whether I ever want to work abroad and be apart again." The scripts have come in like confetti, and her agent has had a firm offer a week from Hollywood. But she has turned them all down and won't move far from home. Even the film she has signed up for after Quills will be shot in Britain.

Winslet's family are still important players in her life. In typical style, she delivers the latest on them: father, Roger, great actor and unsung hero; mother, Sally, brilliant mum; older sister Anna, married five weeks before her, performing with disabled children with fellow actor husband Ed, in Reading; younger actress sister, Beth, in a small-budget movie; 18-year-old brother, Josh, just succeeded in his A-levels and about to take a year out before university. Winslet is not practising to deliver a dog's dinner of a speech like Paltrow, in which she cried her way through thanks to every member of her family, at the Oscars this year. But after her performance in Holy Smoke, she would do well to start rehearsing right away.