Looking at your biography, the TV work you did, you had a run of period dramas and then a run of more contemporary material. Was that by accident or design?
I don’t know. I think it was a time when all the period dramas were out. I did Tom Jones and Rebecca and Poldark. They were the parts of the young girls from that time. I remember when Peaches came along I could get out of the corset and put on a pair of jeans [laughs].

You did Sex and Death, which was very contemporary and edgy.
Yeah, but I only had a small part in that. I’m kind of getting typecast with comedy at the moment, or I have been, and the next week I’ll get something like Blasted, which is a play at the Royal Court and completely at the other extreme. So I think as long as you can vary your characters and vary your jobs then that keeps your mind going and keeps your interest in it. The minute you start relying on old tricks and thinking you know that character . . . If I read a script and think, ‘My God, I have no idea how I’d play that’, then that’s usually the one that I’d want to do.

You mentioned this run of comedies. Do you fear that you might be pigeonholed, despite this other stuff?
Yeah, kind of quirky, redhead, usually slightly naïve but comes straight to point – if I’ve been typecast as anything it’s that. And comedy comes out of that. I wouldn’t say Cherry was like that but a few plays that I’ve done, certainly The Graduate was like that and I did another play at the National which was slightly similar called The London Cuckolds. Then I did Last Orders. It was disappointing it wasn’t in Cannes but it’s going to be in Toronto. It’s opening the festival there so it’s really exciting."

I’ve read your part was expanded for that.
Well, no. It was a lovely, lovely part to start with,and it kind of stayed that way. The script didn’t change. I got the job on that script and it didn’t change, so don’t listen to rubbish. Because when you read stuff like that you go, ‘I didn’t say that. That’s embarrassing’. I had an amazing time on that job and it was probably one of the jobs that I learned most on. Working with Fred Schepisi, the director, who was just a dream. I play the same character as Helen Mirren but younger. The whole film’s in flashback. I play 1939 to 1954. We do lots of different periods, 30s, 40s and 50s, and Helen Mirren does 60s, 70s, 80s.

Last Orders was one of the jobs in my life that I have wanted so badly and I have got, and I can’t believe that I have. Because its such a lovely part, and to be with Michael Caine and Bob Hoskins. There was about five of us who played all the younger versions of all the big guys, and for all of us lot who are pretty much unknown, we just couldn’t believe our luck. We were like puppy dogs. We were so excited to be there and it was such a beautiful script.

Is it quite a dark film?
It can be sad but there’s so much humour in it. And the humour comes out of the human condition and friendships and loyalties and marriages. It’s just about these old guys in a pub and you think that their life is kind of ordinary until you dig deep and realise that there’s a wealth of history and passion. It’s about friendship.

Tell me about Michael Caine.
What gentleman that man is, he’s heavenly. But I didn’t get to work with him because I had to work with the guys who play the young Michael Caine, young Bob Hoskins and the young Ray Winstone. We had the first six weeks of the shoot and they had the last six weeks, and we crossed over by one week. I’d worked with Helen before on Prime Suspect, it was my very first job, and I remember at the read-through thinking, ‘Is she going to remember me?’ This is five, six years later. She came in the room, gave me a big hug, and said ‘Oh I knew I’d see you again, and I was blown away. It was just hilarious. She’s one of my favourite actresses so to have a go at that was kind of wonderful."

She has theatre background as well, like yourself.
I just love her career. I think she’s the dog’s bollocks. She is very choosy about what she does but at the same time she always plays really good characters. I really respect her.

Is she one of the people that you have always looked up to?
After I did Prime Suspect, yeah. She was just a goddess to me. I thought she was just incredible.

Where does your heart lie, with the theatre, TV, cinema?
It’s whatever I’m working on at that point. I’ve done more theatre than I have film, so film is much more of a new thing for me and I feel like I’m still finding my way. That’s exciting and the challenge lies much more in film. Theatre takes up, if you’re doing a run for two months you do a month of rehearsals, it can take up your life for three months and that’s amazing, but you have to have the stamina and the energy to do it. If you’re working with good people like I am, then you’re lucky to be doing it.

Acting is my passion so if I’m working on a terrible play than that can be terrible. But if you speak to most actors they'll be wanting to work in film when they are in a play and theatre if they are working on film. So I think we’re really all a fickle bunch.

Does the snobbery towards the cinema that used to exist still pertain within certain theatrical circles?
[takes a breath] I haven’t come across too much of it. I think nowadays, especially young actors, we’re grateful for any work we can get, without sounding desperate. Of course you would rather do a huge film than be in EastEnders, that goes without saying, but if you need to pay the rent you’re going to do that episode of Casualty. If you’re worth your salt as an actor, I don’t think people hold that against you. I certainly wouldn’t hold it against anybody or go, ‘Oh God, how could you let your art down?’. I don’t think there’s the breed of theatre actors there was before, because the repertory theatre system is largely non-existent now. More actors are coming out of drama school where they’d jump into a rep for a year or two and that would be your career, or you’d go into films. Nowadays you’re more seeing actors who want to do both. I think if you’re good actor I think you always want to go back onto the stage just to prove to yourself that you can do it.

Do you miss the energy that passes between an audience and yourself when you’re in front of the camera?
Absolutely, that’s why you can do a show for nine months and it will be different every night because the audience react differently to things.

Do you not miss that when you’re making a film?
I sometimes think that if I’ve done a long run on a film and I’ve gone in to do TV, I will miss it, because it’s the old cliché of film that there’s lots of hanging around and sometimes you don’t feel like you’re really working. You’ll get to do a little bit of a scene one day, and then you have to wrap because it’s the end of the day and you might not get around to it for the next few days. Sometimes there isn’t enough time to do the detail that you can do when you’re doing a play, so there are different frustrations I think in both of them. It’s so difficult to compare and say which is the better or which is the hardest. You can have a great day’s filming and then you can have a terrible day and never want to do anymore filming ever again.

You’re being touted as part of this new, rising generation of young British stars by the Sunday Times.
It’s all very funny, I don’t know what that’s all about.

Do you perceive yourself as being part of something like that, or is it something that’s being imposed on you?
I’ve been working now for nearly 8 years, since I was 17, and I don’t feel like a newcomer. I feel like newcomer in the sense of my identity for Joe Public to know who I am but in the industry, you know, I don’t feel like this is all a new thing for me. Doing these interviews is quite a new thing, but I’ve been working for a certain amount of time. But every year you see in magazines new, up-and-coming things, and you never see them again. So for me I got to wear a nice Versacci dress and get my hair done, and get pampered and it was lovely to be considered that for that month, but I really don’t take it that seriously."

Having worked for as long as you have, do you find it a little irritating that because you have done some film work rather than theatre, people are suddenly standing up and taking notice?
The profile for film is so much higher because it reaches a far bigger audience.

It must be galling, though.
It can be because I’ve done quite a few leads on stage now. It can be frustrating when people assume that you’re new to it. For me it’s nice to be recognised as somebody that could be up-and-coming because that gives me an opportunity to get my face shown and then get the jobs I don’t get now because I’m not a name. Every young actor comes up against that. Because the more good work you do, the more successful you get, the harder it gets in a weird way, because it’s kind of different levels. You get to that level just before you’re going to get well known, but you’re not well known enough so therefore you can’t play all the big leads in all these big films because people don’t know who you are and the film won’t sell. That I know from most of my friends is the most frustrating thing. Because you can get up into the top two or three for a part, and then they’ll say, ‘We really liked you, we really think you’re great, but the producers want a name’. So you go, ‘Well why did you see me in the first place?’ That can be really frustrating, so this, for me, if it can get me a profile where I can suddenly make a film or be in a film I can help sell, then I’ve got more of an opportunity to do a wider span of work..

So is film where you’d like to work more in the future?
Yeah, if I could do one really nice play a year – this is my plan at the moment. But of course you can’t really plan because I might get offered a job tomorrow then not get a job for three or four months. You have to take what comes up. At the moment I've done more theatre than film, now Peaches is coming out and Last Orders will be coming out, I’d like to take advantage of that and continue to learn.

Do you see these as a defining moment?
It's a moment, but it may not be defining. I don’t know how big or little it will be but I would be a fool not to try and push it. This is the first time I’ve had a PR and it’s all really rather weird. It’s exciting that it could open up new doors but as long as it’s not the be all and end all. I have to say that I am not the most ambitious person in the world.

So the work’s the most important thing for you?
Definitely, definitely. It must be nice to go to these parties and show your face and be bit recognised, I’m sure that must be great for a first few months or so. But I think I would just find myself in the corner, wishing all my friends were there, and going why am I here?

So where did it all start?
I can’t remember where it started. When I was very young I was always grabbing all my friends from down the street and making them put on plays with me. But I never, ever, ever, in my wildest dreams, thought that I could be an actor because I come from a working-class family."

What do your parents do?
My dad’s a police officer and my mum’s a secretary. We’re a kind of two-up, two-down, very normal suburban household. I went to a normal secondary school. Other people do those jobs, you know? I forgot about it, kind of grew out of it, went to school and I had two brilliant drama teachers and that was it. They gave me plays to read and I just kind of felt that that was it for me. It wasn’t like, this is what I want to do but it was the only thing that pushed my buttons and I was good at it. That was when I was at secondary school.

Where did you go from there?
We put on plays every other week, there was a bunch of us at school who felt the same and we had a student drama teacher who came to tell us about this showcase he'd been on called The Casting Couch. I decided, being the arrogant 16-year-old I was, I'd have a go. So I wrote off a letter to the artistic director saying, ‘Please, please see me. I’m 16 years old, I’m great, I think you really need to see me and it would be a loss if you don’t’. She didn’t see me, but about 6 months later I got the audition and I was actually the youngest person to get on it. I got on it and I got an agent from it.

It was the scariest thing I’ve ever done in my life. I now look back on myself at 16 and go, ‘You’re a nutter’. The older I get the more I want to step away from it and not be in the spotlight and not have any attention. Then I realise I’m kind of in the wrong job. But that’s how it started. I got this agent and she gave me my first audition, which was Prime Suspect, it was a complete fluke. Before I knew it I was doing my last year of A-levels and I just had to ask my headmistress if I could take 2 months off to go up to Manchester to film. They did and I came back and that was it: the bug was there. I wanted to go to drama school, my drama teachers were very keen that you go and learn your craft, but I didn’t have the money to do it, that was one, and I was getting more work. So I thought I’m 17, let me have a go. I’ll see what happens. I got episodes on TV, that was then and I never went back.

I was very lucky to get into theatre and before I knew it … I can’t believe it’s been so long. It’s only been this year that I haven’t felt every job has been my first. This year has probably been the one where I feel I don’t know much but I probably know a little bit about myself, what I want to do and my capabilities.

So has your confidence been boosted this year?
I can believe that I am an actress now rather than winging it. I do believe that I have learned a lot through working with such great directors, and great actors. I have kept my eyes open and ears open, I have a constant need to improve and make sure that I’m not lazy. It’s very easy to sit back on your laurels and go, ‘Yeah, I’m doing it’. I’ve been fortunate enough to work with great, great people, so for me they were my training. When I was at the National I worked with the Voice Coach Patsy Rodenberg, who works with RADA and Guild Hall. I had a one-on-one with her and I felt so privileged. Then I was working with her again on Blasted so I feel like I’ve done my training even though I didn’t go to drama school.

Do you think that if you had gone to drama school that self-belief might have been there a bit earlier?
I think you have to get your grounding yourself. People will tell you you’re doing it but that full belief never arises, you feel that you’re going to be rumbled at any minute. Someone’s going to tap you on the shoulder and ask you to leave. I don’t know if I had gone to drama school that would have happened. For me, the thought of drama school did frighten me, because at that age it was something very tangible and very private and scary and I didn’t want to talk about it too much. I wanted to get a script and work with people and do it and then leave it. That’s just the way I work. I’ve come out of that a lot more as I’ve got older and learnt a lot more, but at that age, if I’d gone to drama school, I think my confidence levels could have dropped. I think drama school is tough, I think it’s hard, and I think you have to be a tough cookie to go through it. My strength lies in other places than that.

Would you say you’re more intuitive?
Yeah, definitely. It started out pure intuition because it was raw talent. It wasn’t anything that was sculpted or moulded or refined to make it a proper school.

One imagines drama school could knock that out of you?
Well that was my fear. Everyone says drama school can knock you down to build you up, but I don’t know if that is true. I know people that have had great experiences and people who have had bad. I just knew that it was mine and that any love I had for acting was so delicate at the time that if I had gone to drama school to talk about the metaphysical aspect of theatre, what is it and how you find a character, then the magic would have been lost. But now I’ve learned that’s not the case. At the time I would have rather just done it. Don’t use your head about it too much, whereas now I’m learning that if you do use your head a little bit, you can be better.

Peaches is released Friday 12th October