Still the Kate we know and love?

PICTURE GALLERY: Evening Standard Film Awards

Winning the much-coveted Evening Standard best actress award, in front of an audience including Maggie Smith, Pierce Brosnan and Mick Jagger, was the culmination of a heady month for Britain's most-feted actress in waiting (Dame Judi Dench still retains the title).

In the past few weeks she has been nominated for a Golden Globe, stolen the show at the premiere for Iris in the company of Cherie Blair and been photographed strolling in Beverly Hills with her new boyfriend of five months, director Sam Mendes.

It's tempting to compare Kate's experience with that of Nicole Kidman: both have divorced, weathered the storm and seen their careers thrive despite it all. But what has happened to Kate is on a more dramatic scale. In a matter of months, she has been catapulted from homebody British actress to superstar, from working mum to one half of the A-list couple every Hollywood soir?e would kill for.

The change is already evident. A year ago Kate was a dream to meet: enthusiastic, irreverent, bubbling with stories about demanding directors (James Cameron), childhood problems (weight gain, bullying) and refreshingly eager to share the details of her idyllic life with husband Jim and baby Mia. But since the news broke that there was a new man in her life, there has been a shift away from the old, gasping-for-a-fag-and-ready-to-dish Kate. She'll talk about Mia, about weight, about motherhood and child-rearing but on the subject of the break-up and Mendes she's keeping shtoom, even if she has to suck in her lips to stop herself from smiling when I ask her about it.

The three roles (Hester Wallace in Enigma, the young Iris and Madeleine Le Clerc in Quills) for which she's received the award are women who won't settle for compromise, and it's tempting, in the light of comments she has made since her marriage break-up ("living with someone should be about not wanting to change anything about that person") to conclude that she felt she was being limited by her marriage to Threapleton.

"No, I didn't really think that. At the end of the day, you're playing a part, and my work certainly didn't trigger anything with regard to my marriage. Everything I said at the time surrounding the break-up is absolutely true, which is that it was very much an amicable and mutual situation. The only thing that's been slightly frustrating has been the speculation surrounding the reasons why it happened."

Recently, she hit back at suggestions that her career was to blame. "People have drawn the conclusion that our marriage had broken down because I was so busy and Jim was left holding the baby. But Jim was a heck of a lot busier than I was, believe me."

She is keen to point out that since Mia's birth, 15 months ago, she has deliberately limited her work commitments. "I ended up only working for 11 weeks last year, so I've completely been around with Mia," partly to set the record straight and because she acknowledges her responsibilities as a role model. "I'm immensely proud of that. I don't sort of think: 'Oh, God, I wish they'd stop talking about me'. One of the most wonderful things is when I receive letters from mothers of young girls who have had eating disorders and no longer do because of things I've said or because they've seen some photo."

It's said that even Jennifer Aniston has a picture

of Kate on her fridge because "she's one of the good ones". "Apparently she has," says Winslet looking slightly bemused, "which is really lovely". Perhaps unfortunately for Kate, the combination of her choice of roles (invariably gutsy women), her openness in the past, her emphatically unponcy approach to life (bangers and mash at her wedding reception, an affection for expletives), has led us to single her out as the genuine one, most deserving of our affections. So the fact that she has dropped four stone, ditched the humble husband and taken up with possibly the most-talked-about director of the moment is legitimate cause for alarm. Has Kate changed, is what we really want to know. Was she ever good, old Kate in the first place?

The answer is probably yes and no. She is naturally chummy and down-to-earth and for the youngest actress to be twice nominated for an Oscar (for Titanic and Sense and Sensibility), it's well advised to stick with the earthy, unspoilt approach. But Kate was always super ambitious and, while it may be possible to sustain the dressing-gowns-around-the-house persona for a while, anyone intent on making it big must get with the star programme eventually.

Cue the highly influential boyfriend, the Dolce and Gabbana outfits (as opposed to Joseph this time two years ago), the confidentiality clause agreed with the ex-husband, and the new hardball-playing LA publicist who asks for, but doesn't get in this case, copy approval before granting interviews. And, maybe, a little bit of attitude, as Mick Jagger hinted in his Channel 4 documentary when he mimicked her refusal to attend the premiere of Enigma, the film that he produced. "That is just Mick," Winslet said in response, "and he impersonates people. He is very funny." But it would be remarkable if recent events had not affected her, if not, as some who know her say, "completely transformed" her. "She has become very tough," says one. "She's started really going after what she wants, whether in terms of films or public profile or her personal life. It's as if she has woken up to who she is and what she needs to make her happy."