Her face is almost entirely free of make-up, her hair pulled back into a slightly dishevelled ponytail as she sips herbal tea and chats animatedly about her life and work. If it weren't for a publicist lurking outside and talk of yet more awards encircling her, you'd think you were talking to a normal and somewhat harried mother of two. (Her daughter, Mia, is six and her son, Joe, is three.)

At the time, Little Children - due for release in Hong Kong in spring - is surrounded by serious awards buzz. In it, Winslet plays Sarah Pierce, a mother who is part of a community of parents living in a middle-class Boston suburb, whose lives are inextricably linked - especially when a supposed child molester comes to the neighbourhood. Sure enough, in addition to Winslet's Golden Globe nomination, the film is nominated for best picture award and best screenplay (by director Todd Field and writer Tom Perrotta, who wrote the novel on which the film is based). Predictions are also strong that the film will receive some academy award nominations, which will be announced next month.

'I feel incredibly excited,' says Winslet, before the nominations come out. 'The wonderful thing about Little Children is that when I sat and watched it for the first time, I had this overwhelming feeling of being so proud of this film, because I think it's a huge accomplishment. It was really hard work for all of us, and it was very much a case of team spirit and everyone working towards the same end. And I play somebody who's nothing like myself and that's a huge challenge. So the fact that there's all this buzz around it is an entirely exciting and terrifying possibility.'

Winslet isn't a stranger to that feeling. Ever since she shot to stardom on the back of her role as Rose DeWitt Bukater, the rich man's daughter in love with a poor Leonardo DiCaprio in Titanic, she has been on the receiving end of numerous nominations. By the age of 30, she'd received four Oscar nominations: in 1995 as a best supporting actress in Sense and Sensibility, two years later as best actress for Titanic, in 2001 as best supporting actress in Iris, and another best actress nomination in 2005 for her heartrending role in Eternal Sunshine of the Spotless Mind.

She 's yet to take home the golden statuette, but Winslet says she never allows herself to think that she's automatically entitled to it. 'I don't think you can ever feel that,' she says, in response to a question about whether she ever feels it's 'her turn'.

'The truth is, I've really been overwhelmed and honoured to have been nominated before, and it's not just the nomination but the company that I've been in, in those moments with the other nominees. That's the thing that's really overwhelming: to think that I could be as good as some of those people. And the truth is, I've known instinctively that I wasn't going to win, but it's an exciting and nerve-wracking experience nevertheless.'

Her path to stardom was, in many respects, almost conventional. Winslet was born in Reading, Berkshire, to parents who were both actors. One set of grandparents had founded a local repertory, and her two sisters are also actresses.

She did some commercials and worked in television, initially in a children's science fiction show on BBC. Her first feature film didn't happen until 1994, when she was in Peter Jackson's Heavenly Creatures, playing a teenager who helps her best friend murder her mother.

Then it was on to Sense and Sensibility, with Emma Thompson, which made her almost a household name in Britain. And after Titanic, which went on to become - and still remains - the highest-grossing film in history, Winslet almost overnight knew the meaning of stardom.

Winslet brings her serious acting credibility to every role, even one as seemingly light and fluffy as her part as Iris, a writer of wedding announcements, in The Holiday. Her devastation when she finds out that the man she's been in love with for years (played with caddish appeal by Rufus Sewell) is going to marry someone else, is about as real as it gets. Her performance, alternately touching and amusing, is pitch-perfect. Romantic comedies rarely attract Oscar attention, but Winslet's performance alone is worth it.

It's also the first time Winslet has played a contemporary British woman. (Her numerous roles in period dramas have earned her the nickname Corset Kate. Her more modern-day roles have been American characters.)

'Subconsciously, I didn't apply any different thought processes to doing it just because it was a romantic comedy in a totally different genre,' she says. 'When you say the words 'romantic comedy', you imagine something lighter and possibly easier, but it really wasn't.

'I know I'm playing a contemporary English person, and therefore you tend to think that it would come naturally and easily and really be just a different version of myself. But the truth is, Iris is nothing like me. It was very scary, but I didn't have anything to hide behind - no wig, no accent, no corset. It was very much me, and it was surprisingly challenging.'

Winslet says she was also reminded of her own younger days. In the film, her character goes to Los Angeles for the first time, in a home-swapping holiday gig with Cameron Diaz's feisty film-trailer editor Amanda, who gets to live in Iris' pad in rural Surrey. Winslet says when she first came to LA, she was 19 'and terrified'.

'But it was the same as it is for Iris, leaning out the window, thinking how the roads are so wide and look at all those incredible houses and palm trees. LA is really a beautiful place, and that's what it is for Iris - and a perfect antidote to what she's experiencing in her life.'

Married to director Sam Mendes, Winslet has a stable and happy family life, although she says she's always been 'a bit of a hopeless romantic'.

'As an actor, you subconsciously draw on your own experiences all the time,' she says. 'With Sarah in Little Children, there weren't that many things I could see immediate parallels to, but I do remember certain feelings and sometimes they weren't nice and other times they were helpful and pleasant.

'But I think we've all had that person we've been completely fixated on, who we really believed was going to turn around and say, 'I've loved you all along.' Iris is so honest and vulnerable and in love with love, and wants to be adored and looked after and appreciated, and those are really lovely qualities to play as an actress.'

A veteran of the independent film scene, Winslet says the high gloss of a big-banner studio production took a bit of getting accustomed to. 'I'm used to being in independent films where you get a trailer, but you get there and maybe the air-conditioning doesn't work,' she says. 'I actually love that, because it's a little like going camping. But when I got to the set of The Holiday, and they showed me to my trailer, I laughed when I first saw it because I didn't know they made trailers this big. There were a million places I could put my bag.'

She's hoping, at some point, to be able to collaborate with Mendes, but says she doesn't agonise over the possibility as other married power-couples might do.

'We'd love to work together. We haven't come across something that we both feel that, yes, that's the thing, most definitely. People always ask me what I think that would be like, if we would have arguments. We don't have a huge amount of conflict in our relationship anyway, so I think it would be a laugh.'

The Holiday opens on Thursday