Tamzin Outhwaite: Non-blonde ambition

EastEnders catapulted her to stardom, but now she's finding her full range at the Royal Court. Sam Marlowe asks her about her new role in cutting-edge theatre

She made her name in EastEnders as the glossy Melanie Healy, the siren of Albert Square. She's been voted Sexiest Female in the British Soap Awards for three years running, and she features regularly in lad-mag top-totty polls. But now Tamzin Outhwaite is exploding her own myth. In Ché Walker's hard-hitting drama Flesh Wound, presented in the Theatre Upstairs at the Royal Court in London, Outhwaite plays a desperate and decidedly unglamorous young woman at the centre of a dysfunctional family on a London sink estate.

One sign of this change of direction is obvious on meeting her: she is no longer blonde. "Sex symbol", she says, is not a title she particularly relishes, and she seems to have taken a perverse delight in dyeing her trademark tresses a muddy brown for Flesh Wound. But if she thinks she's made herself unattractive in the process, she's mistaken. Outhwaite, 32, is tall and willowy, and her delicate features are alive with energy and enthusiasm. She has a winning smile and her big brown eyes sparkle. So, even though she's wearing a tatty T-shirt and jeans and barely a scrap of make-up, she looks stunning. She poses happily for the photographer in the Royal Court's upstairs bar before nipping out on to the balcony for a fag. Then, disarmingly, she announces: "I've just got to have a quick wee," and dashes off, before we settle in a quiet corner to talk.

Has going dark actually made her feel different? In fact, she reveals in her husky, Essex-inflected tones, she's not a natural blonde at all. "I'm a kind of mousy mid-brown. Darker hair makes me feel there's less of a spotlight on me. It feels like I can get away with more. Because it's all tied in with the character I'm playing, it's like a licence to let go. I don't have to be groomed all the time, it's really refreshing."

Tamzin, the eldest of three children, was born in Ilford to East End parents. Her mother is a financial adviser, her father owns a cab company. She says, with a chuckle, that there was "very minimal creativity" in her family – her parents are both business-minded. So how did they respond to their stage-struck daughter? "My dad was a bit horrified when he'd have the boys round on Cup Final day and I'd stand in front of the telly, when Arsenal were about to score a penalty, wearing my tutu and going, 'Dad, Dad, look what I learnt in ballet!'"

But they supported her ambitions. She trained in singing, dancing and acting at the London Studio Centre, and landed a string of musical-theatre roles after graduating. She enjoyed the work, but says her heart was always set on straight acting. "If you can sing and dance, it's a way to make a decent living. But often, great musical-theatre actors find it really difficult to make the transition to straight work. They're dismissed as 'West End Wendies'. But some of the people I met back then are among the best actors working."

Outhwaite got her chance to cross over when she worked with Alan Ayckbourn at the Stephen Joseph Theatre in Scarborough. She was in his production of the musical They're Playing Our Song, and was fascinated by Ayckbourn's skill as a director. "It was like watching a master at work. We formed a friendship, and he was very supportive and nurturing." He cast her in her first professional straight role in his play Absent Friends, and for a two-year period she worked with him extensively.

Then, just a week after returning to London, Outhwaite won the role of Mel in EastEnders. Tamzin seems to have taken it all in her leggy stride. "Nothing can prepare you for something like that. I had a brilliant time and I learnt loads. But like everything I've done, it was another stage of learning the trade. I never felt like, 'Now I've made it, the world is my oyster.'"

Since leaving EastEnders ("three-and-a-half years was enough; I never wanted to become part of the furniture"), Outhwaite has chosen her projects wisely. She talks about learning her craft and developing as an actress, and beneath her easy manner there's seriousness and determination. She played a traumatised single mother in Dominic Savage's improvised film Out of Control, an uptight corporal in the series Red Cap (a role to which she returns next month) and, most recently, a manipulative fraudster in the BBC drama Final Demand.

She dipped her toe into the Hollywood shark-pool last year, but says she has no desperate urge to make it big in the movies when things are going well at home. She's also picked up a couple of lucrative modelling contracts, with Avon cosmetics and the Spirit clothing range at Debenhams. With just a flicker of defensiveness, she stresses that modelling pays for more artistically rewarding endeavours. "It provides me with the financial security to be able to choose to do theatre. I feel quite all right about it. I chose one cosmetics range and one clothing range, and I chose carefully."

If more theatre is on the cards, could it be that Outhwaite's reported ambition to play Lady Macbeth is due for fulfilment? As soon the question is out of my mouth, I realise I have committed the cardinal sin and spoken the M word. Outhwaite's eyes widen in horror. "You can't say that in a theatre!" she gasps. And she leaps up to go through the strange little actors' ritual that supposedly wards off the hex. I watch, part mortified and part amused, as she spins round three times, spits, swears ("Bollocks!") and goes outside to knock on the door for readmittance.

I apologise, and she looks quite cross, but the performance is so ridiculous that she's soon smiling again. On the subject of the unmentionable Scottish play; that, she says, was a throwaway remark to a journalist who asked her what her dream role was. Lady M was the first that popped into her head, but "I change my mind every day, so it's not a burning ambition, no. Anyway, I've played a lot of strong women, so I feel I've covered some aspects of that character."

In Flesh Wound she's facing a genuine challenge. She says the play is "a little shocker, the sort of thing the Royal Court does very well. It's nice to do some raw, edgy drama." It's directed by Wilson Milam, the man behind the RSC's dazzling (and gory) production of Martin McDonagh's The Lieutenant of Inishmore. Outhwaite says he's pushing the cast hard. "You have to be open as an actor, you have to be able to let your demons in – and out. And I'm getting a chance to do that, which is great."

Whatever demons she has, Outhwaite keeps well hidden. But one must be the stigma that follows soap stars when they try to go legit. "It's still surprising when you get a job and they tell you about the great cast that are gonna be surrounding you," she admits. "And you think, 'My God, how did you get them? Do they know I'm in it?' Because there's a feeling that other actors might just dismiss you."

Will some say she doesn't belong at London's cutting-edge theatre for new writing? "Only if they haven't seen anything I've done since EastEnders," she counters. "I feel I've earned my stripes. People always want to see you slip up. You have to keep reminding yourself that you're doing it for yourself, to learn and grow as actor – and as a human being. You just have to take it on the chin and move forward."

She'll certainly be subject to scrutiny in the tiny Theatre Upstairs. Does that degree of intimacy with the audience alarm her? "I think it'll add to the truth of the performances," she says. "We'll feel quite vulnerable. Actually, it is scaring me now, talking about it. So," she adds, with mock irritation, "thanks a lot, I was fine before!"

More reflectively, she goes on: "But I think if it didn't scare me, I'd be in the wrong job. I've decided how to choose my roles. When I read the script, if it scares the shit out of me, it's time to take it. If it doesn't, it's not worth doing." Blondes might have more fun, but natural brunette Tamzin Outhwaite looks set to earn herself some real professional respect.

'Flesh Wound' is at the Royal Court Theatre Upstairs, London SW1 to 7 June (020-7565 5000)