Keeley, the reluctant temptress

It doesn't come easy trying to imagine Keeley Hawes, gamine young star of steamy period dramas such as the BBC's Wives And Daughters and heavily cleavaged ones such as the Diana Dors biopic Blonde Bombshell, sitting at home knitting. She says that her sister has to cast off for her - but still, this is surely not the way the TV-watching public sees this actress who can simmer away with the best of them. Certainly if you catch her in her new film, The Last September, you wouldn't expect her to be knocking out woolly jumpers on her nights off.

The film is stage director Deborah Warner's first movie - just like American Beauty was Sam Mendes's and, like Mendes, Warner's debut is being hailed as the work of a hot new talent. In her version of Elizabeth Bowen's novel set in the last days of Anglo-Irish Twenties Ireland, Hawes plays the full-blooded Lois Farquar, a budding 19-year-old who is loved by a British soldier, played by David Tennant, but is infatuated with a Republican, played by Gary Lydon. 'When I first read it I thought it was a bit shocking, a bit contentious, to play an Anglo-Irish girl in love with an IRA man - but things were different then,' Hawes says. 'I read up on the history of the IRA and at first I felt a bit, "uh-oh". But this is a film about people, not history. I hope people will see it as such.

'Making it was also very "people". We were all living in a crumbly, gracious old house just down the road from the one we shot in. It became rather like living in the girls' dorm - in my corridor there were my co-stars Maggie Smith, Jane Birkin, Fiona Shaw and Deborah [Warner]. Good people to share with and somehow, charmingly Irish.'

Keeley Hawes, despite her Irish name, has no Irish links. She comes from Marylebone, still lives in the area, and is looking for a house in Esher. 'I'm a regular Londoner and homebody. I don't go to openings and don't even belong to a club. I don't go to the gym or have a personal trainer. It's showbizzy enough for me to walk out of my door and see Joseph Fiennes running by, or cross the street on the pedestrian crossing with a pack of film-makers off to lunch.

'My most recent starry moment was buying potatoes in Marks & Spencer in my puffa jacket when a dear old lady recognised me. I must have been looking exhausted because she said, with great kindness, "Now, you go off and have a good rest, dear."'

Hawes talks in clear, ringing tones. She laughs a lot at herself and has the ability to pass unnoticed, although with her tasty lips and almond eyes she can be absolutely gorgeous. She was 'discovered' walking in Oxford Street aged 15 'by one of those men paid to ogle little girls' she says, wrinkling her nose. She joined the Select model agency, posed for magazine covers, did loads of fashion and beauty and got to see the world. 'I was never a catwalk model. My height's right but I'm a bit hippy and busty. I'm still taller than every male I've ever worked with. I'm always standing in ditches.'

After two years she quit modelling and it was while she was doing work experience at Cosmopolitan as 'something in the fashion cupboard' that a phone call came through from a casting agent. He asked her to come in for an audition. He'd seen pics of her during her modelling days, when she was the waif with short hair in campaigns for Sisley and Benetton. The job was Dennis Potter's Karaoke, playing Linda Langer, and Hawes was just 17. 'Fate seems to have called me back into the arena,' she says, slightly bemused. 'I got the job. It's not something I would ever have chased. If I hadn't got it I probably would have ended up as one of those women's magazine stylists with dozens of handbags filled with lipsticks and nail polish. The film business is a hard industry to penetrate.

'I have to admit to believing in fate. It all started when I was in primary school and the drama school I went to, the Sylvia Young Theatre School, moved almost directly opposite my house. The closest I had come to a theatrical background was my granny taking me to matinees of musicals and pantos as a little kid. Yet my mum one day asked me if I'd like to try and get in to the theatre school. I did a little piece from The Pied Piper and that was it.'

Her contemporaries were several of All Saints, Emma Bunton and Denise Van Outen - 'in those days just Denise Outen'. 'We weren't one of those families who spent their time watching movies. My father is a cabbie [Caroline Aherne is apparently a damned good tipper]. He and my mother met in a cafe, the Regent, up the road from where we live. She was 18 when they married and they had the four of us. Every year we used to go on holiday in the cab, with the dog, to places like Tintagel.

'There was not a lot of drama in the family. Still isn't. My brothers are cabbies, my sister's a mother of two. We all still see a hell of a lot of each other. It keeps me sane and normal in the mad business. The only concession to my "fame" is the scrapbook my gran keeps. It's actually a Will Carling scrapbook, with pictures of him and Princess Diana. On a couple of pages at the back of the book are a few pictures of me from magazines where she's cut off just my head and stuck it in.'

She says she worries that her roles are too sexy for her grandmother, who's 86 ('Oops, shouldn't have said that - last time I did I got into trouble because, she said, everybody thought she was 65') to watch. 'My granny used to work laying carpets. She laid the carpets in Buckingham Palace with my auntie. It was her trade. They also did Kensington Palace and saw William and Harry when they were tiny.

'I wouldn't like her to see Complicity [a film Hawes recently made with Jonny Lee Miller based on Iain Banks's novel] because I play a nymphomaniac. It was bang up-to-date and very nice to do something that wasn't corsetted-up and Victorian. Very liberating.'