Petite and gamine, with dark doe eyes and deep-set dimples, Carey Mulligan is impossible to ignore. Staring out of the film festival programme earlier this year, her photo sat above a picture of Audrey Tautou, the similarities so striking many may have thought the French actress was also the star of Mulligan's film An Education.

If her still image is alluring, it's not a patch on her onscreen presence, which will charm you so completely, you will wonder where this young starlet has been hiding until now.

You might have caught a few seconds of her in Johnny Depp's latest Public Enemies - complete with platinum blonde wig. Or as Keira Knightley's little sister Kitty in the 2005 adaptation of Pride and Prejudice.

But this is the first time English-born Mulligan has taken the lead in a film, playing Jenny, the innocent schoolgirl-led-astray.

And despite working opposite industry heavyweights Peter Sarsgaard, Emma Thompson, Sally Hawkins and Rosamund Pike, Mulligan steals the show. She is, without doubt, a star on the rise.

Of course it helps that An Education, written by Nick Hornby and based on the memoirs of journalist Lynn Barber, is itself a gem of a film.

Set in the smoke-filled clubs of 1960s London, the story recalls the affair between Jenny, a pretty young schoolgirl with aspirations of going to Oxford, and David, a mysterious older man with questionable morals, who charms both Jenny and her parents into allowing a relationship to form between the unsuitable parties.

It's a classic coming of age story - and a lighter one than that originally described in Barber's memoir. Mulligan says they could have told a darker story but she found Hornby's retelling a more poignant tale.

"These characters all have faults but are still liked. You still feel for all of them. I find it so hard to watch films where I don't feel for the characters in them.

"I think it's really important that we found David sympathetic. I love how he painted him as this man who's always a bit on the outside and trying to work his way in. I think Nick writes these parts brilliantly. A lot of his books have these kind of men in them."

It was also important that Jenny wasn't seen as a victim in the film, says Mulligan.

"She's really intelligent and I think you see her driving the intimate side of their relationship more than you see David doing it. She's not being forced into doing anything. She goes into it with her eyes open."

Much like Mulligan herself, who has cleverly crafted a career in theatre and film, without ever taking a role she didn't truly love. "There's just no point really, unless you're going to be really upset if you don't get it. You don't want to play a part that you could happily let someone else play."

It's a confidence she gained after playing Nina in the lauded 2007 revival of Chekhov's play The Seagull.

"That is the most extraordinary theatre role for a young actress and it's set the bar quite high for parts. I walk away quite happily from parts that feel decorative or just the 'love interest'. Anything two-dimensional. If I can read a script and go 'I know exactly how I can play that', then it's not interesting. If it worries me then that's usually a good sign."

And the most interesting roles, the most challenging jobs, aren't necessarily the most obvious ones, says Mulligan, who admits she finds smaller, bit parts trickier than playing the central lead.

"When you go in to play a supporting role, you go in to play a really small part and you have a really small amount of time to make your impression on the film.

"That can be really daunting. You meet the whole crew and you have one, two days or a week to make a fully rounded character and fit in with the tone of what everyone else is doing. I've always found that terrifying."

It's the reason she appeared for what she jokes was "three frames" in Public Enemies - despite having earned her leading lady stripes on An Education.

"I'd met Michael [Mann, the director] and thought he was fascinating. I loved his movies so I auditioned for that small part. It was one scene longer in the original script. I just thought it would be amazing to work with him for just a day or two days, so I jumped in."

Working on the big-budget film gave Mulligan a fleeting taste of the Hollywood lifestyle, but the 24-year-old has no aspirations to jump the Pond. Her next two films Brothers and Brighton Rock are British productions - featuring yet another sterling line-up of award winners, including Helen Mirren, Pete Postlethwaite, Keira Knightley and Sally Hawkins.

"I've never really had a plan," she says earnestly. "I've just been going for the best parts that I can get. I'm sure it would be great fun to do an action, blockbuster, mad film one day but I usually find I'm happier playing human stories and a lot of those are independent films."

Who: Carey Mulligan
Born: 28 May, 1985
What: Plays Jenny in An Education, based on the memoirs of journalist Lynn Barber
When: In cinemas October 8