Vanessa Kirby: A Dickens leading lady with a dark side

The first time I saw Vanessa Kirby, she was dead within 20 minutes. Yet the rising British star made a considerable impression as the luckless debutante Ruth Elms in this year's hit BBC2 series The Hour. Beautiful yet fragile, her blonde hair piled high, her presence haunted the show (as well as Ben Whishaw's enamoured investigative reporter) almost effortlessly. Little wonder Paul Taylor, in these very pages, noted Kirby was "a star if ever I saw one", when he reviewed this year's Royal Court production of Anya Reiss's The Acid Test, in which she starred.

Today, thankfully, she's very much alive and in good spirits. We meet in the bar of the Covent Garden Hotel. It's busy and our waiter seems to be rather in a mood when he brings us a pot of tea to share. "Wow, he's really grumpy," she whispers. "I don't see the point of grumpy people." Dressed in a baggy blue-and-white striped sweater and skinny jeans, Kirby is slender, willowy and blessed with entrancing blue eyes. Next to her is a large handbag, heaving with scripts for the TV mini-series Labyrinth – a Ridley Scott production which she is about to start shooting in France and South Africa, alongside Downton Abbey's Jessica Brown Findlay.

This Christmas, Kirby will be on our screens again in a new three-part BBC version of the Charles Dickens classic Great Expectations. She's playing that most heartless of characters, Estella, following in the footsteps of Jean Simmons, Francesca Annis and Gwyneth Paltrow. Kirby "deliberately" didn't revisit any previous versions. "I only really looked at the novel and the script. And I wrote pages of notes. I stuck them all around my bedroom. She's such an ambiguous character. Really difficult, actually. Nothing about what's happening outside is going on inside. There's never a moment where she is at one with herself."

Adapted by Sarah Phelps, who previously wrote a 2007 version of Oliver Twist, it forms the centrepiece of the BBC's celebration of all things Dickens as we approach the bicentenary of his birth in 2012. "It's very loyal to the novel," says Kirby, "but I think there's a raw edge to it and a darkness that isn't in some of the other adaptations." She praises the way it's been cast. Douglas Booth (recently Boy George in Worried About the Boy) plays the orphaned Pip, who falls for the "vile" Estella. "Douglas is 19 and in the previous versions the actors have all been a bit older."

Likewise, Gillian Anderson, who plays the bride-that-never-was, Miss Havisham. Kirby recalls numerous people comment "she's very young" when she's told them that the 43-year-old X-Files star was playing Miss Havisham. "But it's more tragic if you're this stunning woman who has psychologically deteriorated, rather than physically," she argues. That may be true, though Anderson has aged up, looking almost ghost-like in the role. "She looks pretty scary. I remember seeing her for the first time on set, going, 'Wow, is this who Estella has been brought up with?' It made a lot of sense seeing her."

Fortunately, for the 24-year-old Kirby, her Estella will reach the screens before Mike Newell's rival film version, starring Holliday Grainger in the role and a rather glamorous-looking Helena Bonham Carter as Miss Havisham. She seems unconcerned with this; indeed, very little seems to faze her. "I try to focus on each day and try to be the best I can be today," she says. "I'm trying not to worry. I remember a casting director – John Papsidera [who has cast

Chris Nolan's The Dark Knight and Inception] told me, 'The industry thrives on fear.' But the best thing to do is relax."

A wise head on young shoulders, there's something about Kirby that suggests she's in it for the long haul. Certainly, you sense she'd be happy if her career remained in the theatre. Born and raised in London, the middle child of three, it was after seeing a National production of The Cherry Orchard with Vanessa and Colin Redgrave in her early teens that she truly knew she wanted to act. "Sometimes I spoke about it – and I don't think my parents totally thought it was the best thing. I remember my Dad being like, 'You should go and do marketing or PR.' And I was like, 'No, Dad, I'm going to be an actress.'"

At 17, she applied to the Bristol Old Vic – and was told to come back the following year because she was too young. Instead, she took a year off, went to Africa and worked in hospices and schools. "I was teaching people my age... and I felt less judged there than I did here, weirdly." I ask what she means by "judged"? "When you're 18, it's about what you look like or who's going out with who. Very teenage concerns. I went to a very academic school but I never really quite... I think because not that many people were particular creative or arty, I felt a little bit different."

While she speaks of her "lovely childhood" – her father is a prostate cancer surgeon, her mother a former editor of Country Living – you can't help but think she might inspire jealousy in others. When she was living in a flat outside Cape Town, her flatmate – an English girl – set upon her. "She was just really drunk and she literally beat me up. She got sent straight home. We'd been reasonably good friends before. She's just a very angry person. At the time it was absolute horrible. I was really bruised everywhere – but nothing broken. In a way I was quite pleased. I'd survived." Ironically, she'd been studying a module in conflict resolution at the nearby university at the time.

She returned home to study English at the University of Exeter – a further indication that she felt no need to rush her entry into acting. The key moment came in one crazy weekend. Offered a place at drama school Lamda, she was then called in to audition for the Olivier-winning director David Thacker, the current artistic director at Bolton's Octagon theatre. A 40-minute chat turned into an intense three-hour session, which saw him offer Kirby roles in All My Sons, Ghosts and A Midsummer Night's Dream. "He said, 'Are you going to accept? I'll give you the weekend [to decide]. But I think you should do it. It would be the biggest mistake if you didn't.'"

Kirby took on the trio of roles, withdrawing from Lamda. "That was quite difficult. I'd always thought I was going to drama school to train. That's what everybody did do, and I just thought 'that was the way'. But I had to let that go." Following her trio of roles with that most complicated of Shakespearean heroines, Rosalind, in a West Yorkshire Playhouse production of As You Like It, Kirby then found herself in Women Beware Women at the National, opposite Harriet Walter. As a result of this glut of high-profile theatre work, she was nominated in two consecutive years for the prestigious Ian Charleson Awards.

Already, she's been to LA and has an American agent – but is hesitant about Hollywood. "I remember someone saying, 'Go in there and tell them your five-year plan.' And I remember thinking, 'No!' I know what quality of work I want to do, and I know what type of people I'd love to work with. But if you set yourself up... I hate the idea of massive fame. I think the scariest thing for an actor is when your name becomes bigger than your craft or what you can do. Rosamund Pike and Hayley Atwell are actresses who have done it totally the right way round for me. They've got such a solid base of amazing work."

It's a refreshing attitude, one that indicates Kirby has ambitions beyond simply getting sucked into the Hollywood machine. "I want to develop a really good foundation of work here before I think of doing that," she says. Of course, it helps when your next gig is with Scott Free, the company formed by Ridley and Tony Scott. Labyrinth, it should be noted, is not a remake of the 1980s fantasy movie. "People all keep saying that!" she giggles. "There's no David Bowie!" Rather, it's an adaptation of the best-seller by Kate Mosse, in which two women – centuries apart – are linked by the Holy Grail. She's licking her lips at the prospect of working with a cast that includes John Hurt. "I've got really long scenes with him. I can't wait! Apparently, he's great on a night out!"

Confidence seems to ooze out of her. After The Hour, coming up against her hero Ben Whishaw, she stopped getting intimidated, she says. "I saw Hamlet three times when he did it. So that was really scary! Sometimes I was like, 'Oh my God, this is Ben Whishaw!' But you kinda get used to it. You have to, or you'll be a nervous wreck." Truly, she just doesn't look the sort.

'Great Expectations' starts on 27 December at 9pm on BBC1