Jeremy Irvine has spent the majority of his burgeoning career on screen with a broad west country accent, first in Steven Spielberg's War Horse and now as Pip in a new adaptation of Great Expectations. So it's rather odd, in person, to hear him speaking with clipped vowels more reminiscent of Laurence Olivier than Vicky Pollard. "Yes, the accent was quite hard work. I actually spent ages with 1920s recordings of old Dartmoor accents trying desperately to pick it up. Now that I've got it, it's pretty hard to stop. Sometimes I slip into it. I always wonder whether I'll get treated differently with a different accent."
It's no wonder this earnest 22-year-old, impeccably polite though his sentences are littered with swearwords, is curious about being treated differently. Not so long ago he was a jobbing actor from a small village in Cambridgeshire, with one year of LAMDA (The London Academy of Music and Dramatic Art) under his belt and little to recommend him but a stint as a tree with no lines in a Royal Shakespeare Company production and a brief appearance on a Disney sitcom.
But he had, like Pip, great expectations. Along came an audition for War Horse and, after two months of endless recalls, his role as a Spielberg lead – and as a British rising star – was confirmed. In September he appeared in Now is Good, a drama with Dakota Fanning, and he has just returned from filming the prisoner-of-war drama The Railway Man in Thailand with Colin Firth, and A Night in Old Mexico, a comedy with Robert Duvall.
In just two years he has gone from nervous newbie, "freaking out" on the set of War Horse, to a celebrity in his own right unfazed by his co-stars, with a huge teenage girl fan base and, it seems, a famous new girlfriend, singer Ellie Goulding, with whom he was recently spotted at Somerset House inLondon, ice skating hand-in-hand. He is tight-lipped about the latter. "Let's just say it wasn't easy to go on dates before all this [fame] and it sure isn't easy now." Does he feel like he knows what he's doing now? "Ha!" He grins bashfully. "I'm glad I've given that impression. But no, a lot of it's still guess work. Of course, walking onto a set with people like Ralph Fiennes [as Magwitch] and Helena Bonham Carter [as Miss Havisham], you are going to be a bit like, 'God, that's Helena Bonham Carter, you know?' I'm just this snotty-nosed little new kid. But you just try desperately not to think about it." Fiennes, he admits, was a bit intimidating. "But," he proffers diplomatically, "he's playing a really scary role."
This new adaptation of Great Expectations, directed by Mike Newell with a screenplay by One Day author David Nicholls, is, he is keen to stress, the first period film since David Lean's much- revered 1946 version, although there have been several contemporary adaptations and TV series, including last year's by the BBC. But his Pip, Irvine insists, is very different from his predecessors.
"The first thing Mike said to me was, 'Why is Pip such a little shit?' It sounds silly, I know, but there are two ways you can look at Dickens: one is as having these funny, farcical characters and the other is for real. As a child Pip is beaten by someone called Mrs Joe with a stick nicknamed tickler. Funny, right? But this is someone who has been the victim of the most awful domestic abuse. Pip has to look after himself and from that he gets a hardness. His idea of becoming a gentleman isn't a childish whim to get Estella. It's a dark, burning obsession about getting away from this awful, awful life that he's come from."
Irvine, too, has an obsessive streak. When he was out of work, he hired cameras and created a showreel of fake work before passing it off as real to agents. He also turned down a big commercial film in LA after War Horse, he says, doggedly waiting for better scripts. Clearly a hard worker, he is determined not to be mistaken for just some kid who got lucky. For The Railway Man he lost two stone; he shows me a picture on his mobile in which his ribs jut out. "It scared my mother. But it's so hard for someone of my generation to understand what happened to those guys that you have to do absolutely everything you can to relate."
How Irvine – whose real surname is Smith (Irvine was grandfather's name) – fell into acting seems a bit of a mystery, even to him. At 19, he applied for the army, but was rejected after lying on forms about his diabetes, a condition he has had since childhood.A great drama teacher at school had told him that drama school would be like boot camp, really tough. "That kind of appealed to me, not sure why."
His younger self in Great Expectations is played by his 13-year-old brother Toby, after his mum met the casting agent at an after-party. (His mum comes to a lot of parties with him, because it's not really his "scene" and "anyway she likes to spot famous people".)
But Toby, who has the same angelic looks as his brother, right down to the blue eyes and the chin dimple, is, says Irvine, much less perturbed by the whole rigamarole than he was. "I was a bit worried on the red carpet at points because he's so young. When people scream your name and tell you you're amazing it would be so easy to buy into all that stuff, even though none of it is real. But he was just like, 'Well, that was fun, I think I'll go back to school and get back to playing hockey now.'"
There is another brother, currently studying to be a vet at Cambridge ("He got all the brains"). Dad is an engineer and Mum is a local politician. "She makes what I do look kind of farcical. If I ever feel swept up in it all I remember that she's there housing homeless people." Irvine now lives in north London with a friend. In his spare time he like to "claw back some masculinity" after weeks in a make-up chair by doing things like boxing and playing rugby. He's a bit of a history nut too, he says, and has just written a documentary about First World War fighter pilots.
At the end of the interview, Irvine settles comfortably into the corner for photos. He picked out his outfit himself, he says – leather jacket, white T-shirt, James Dean haircut. He is cool as a cucumber, every bit the professional. He may be young, but Jeremy Irvine is definitely here for the long haul.
'Great Expectations' is released in the UK on 30 November