Jeremy Irvine is having the year of his life.

No sooner had he made his film debut as the lead in Steven Spielberg’s War Horse in January than he found himself being asked by director Mike Newell to play Pip in his adaptation of Great Expectations – then Colin Firth wanted him to play his younger self in upcoming war drama The Railway Man.

“Sometimes you read a script and spend a long time saying, ‘Oh well, maybe it could work this way’, but this was just such as ‘I’ve got to do this movie’ moment,” the 22-year-old says earnestly.

“I met Colin Firth and had dinner with him and he was the one that actually got me the role, which was nice.”

Irvine plays the young Eric Lomax, a British army officer who was sent to a Japanese prisoner of war camp during the Second World War and forced to work on the infamous ‘Death Railway’ from Thailand to Burma. The film is based on his memoir of the same title, and Firth plays the older Lomax.

“We kind of share the movie and he was so generous,” says Irvine. “We’d rehearse in his living room and I was thinking, ‘My God, this is the kind of acting masterclass you can only dream of when you’re at drama school’.

“At the time, you’re just working with someone who’s really good at what they do and really interesting, and of course afterwards you go, ‘Wow, that was really kind of him’.”

Between the two war films, Irvine’s branched out, starring in indy weepie Now Is Good with Dakota Fanning, and this week taking on the central role of Pip in Great Expectations.

Adapted for the big screen by One Day author David Nicholls, it stars a who’s who of British acting nobility, including Helena Bonham Carter as Miss Havisham, Ralph Fiennes as the convict Magwitch and Robbie Coltrane as Jaggers.

After War Horse, Irvine insists he wasn’t daunted by bringing to life another well-loved book.

“Obviously, I was terrified, but it wasn’t the fact it was well-known, because this was David Nicholls’s script and yes, there’s been a few TV adaptations but there hasn’t actually been a period movie adaptation since 1946, so I felt there was scope for doing something new and interesting.”

Great Expectations was most recently tackled by the BBC last Christmas, with Gillian Anderson as Miss Havisham and Douglas Booth as Pip. “He did a great job,” says Irvine, graciously.

“It takes 20 hours to read Great Expectations cover to cover, and we had just two hours.

“In the BBC one, they cut stuff I couldn’t imagine losing and I’m sure we did too. They will never be the same [adaptations], it’s like shuffling a pack of cards, they’ll never go in the same order twice.”

For anyone who’s not read Dickens’s masterpiece, we first meet orphan Pip as a 10-year-old living with his sister and her blacksmith husband, Joe, on the marshes in Kent.

A chance encounter with escaped convict Magwitch is followed by a visit to the house of Miss Havisham, who employs him to entertain her beautiful ward Estella.

Ten years later, Pip learns he has been given a huge fortune by a mysterious benefactor and must abandon his lowly life in the country to live as a gentleman in London.

Irvine was picked by Newell for the role because of his youth and good looks. He hides his face in embarrassment when Newell says: “He’s dark, so I thought he would look good in the forge, against hot iron.”

But it was more than that, adds Newell. “At some point Pip would be guilty about the way he’d behaved in his savage climbing of the social ladder and I was interested in how my intuition told me he would play guilt.”

Irvine comes across as more mature than his years.

He’s also extremely passionate about the roles he’s chosen and defends the character of Pip, who’s mortified by Joe’s country ways when he comes to visit him in London.

“You can’t ever see someone as being a terrible person.

“Pip’s been put down his whole life and he’s incredibly unhappy.

“Becoming a gentleman is his one way of getting out of this awful life, so it’s not some sort of childish whimsical idea, it’s this real, deep, driving ambition.”

He’s similarly fired up about doing justice to the story of Eric Lomax in The Railway Man. “I actually got to meet him and his family a little bit and felt a huge responsibility to that story. Unfortunately Eric died a couple of months ago (aged 93), but he knew the movie was being made.

“He was such a wonderful person that I really wanted to try and do it justice.”