Next stop USA: James Corden is packing up for Hollywood

Corden, 36, looks happily exhausted. It’s not just the work schedule. A few weeks ago, his wife, Julia, gave birth to their second child. Things really couldn’t be better for him.

Last time I met Corden he was also on top of the world – although the peak was somewhat less vertiginous back then. It was 2008 and he had just finished acting in and co-writing (with Ruth Jones) two hugely successful, award-winning series of the sitcom Gavin & Stacey. He was about to launch a sketch show with his Gavin & Stacey co-star, Mathew Horne, and had just completed the movie Lesbian Vampire Killers, again co-starring Horne. Both bombed.

When I suggest this is a comeback, his hackles rise. “Well, if my career was in a bad place at a time when I was writing probably, give or take, the biggest comedy show in the country, I dread to think what everybody else’s career could possibly be like. And being in a film that doesn’t work, that’s the experience of most people. If somebody was with Michael Fassbender, they wouldn't say, 'Let's talk about The Counsellor,' which was an unmitigated disaster. If you were talking to Benedict Cumberbatch, you wouldn't go, 'Let's talk about The Fifth Estate,' which could not have been more hyped and then didn't perform. So I don't really know what there is to say about it."

Does he think I’ve misrepresented his career? “No, because [that film and series] didn’t work. But you will not find any person who didn’t do two things that didn’t work, and mine just happened at the same time. That’s all it is.

“But people seem to want to talk about my misses and they don’t want to talk about others, and that’s where I find it quite odd. We’re four minutes into this interview and we’re talking about things that haven’t worked, and I don’t think that would be the case if there were other people here.”

Blimey. All I’d wanted to say was that it’s good to see you back again. But he’s not finished yet. “Yes, but there was nothing to come back from. Work didn’t stop. I was never not employed.” He has a point. If you’re in the creative industries, he says, you have to risk and embrace failure, and learn from it. But, I say, I thought there was an arrogance to the failures. While Gavin & Stacey had been beautifully crafted, the sketch show and Lesbian Vampire Killers were rushed and ill conceived.

No, he responds, it was the opposite of arrogance. “I think it was more a fear of, ‘This is all going to disappear any minute.’” He takes me back to his first great success, in Alan Bennett’s The History Boys. The play went from the National in London to Broadway, and a successful film was made of it. Corden was 21 stone at the time and, not surprisingly, played the fat boy. Equally unsurprisingly, casting directors continued to regard him in the same light. “There were eight boys in the play, and all the others were coming in with mounds of film scripts, saying, ‘I’ve got so many meetings and I don’t know which project to do,’ while you’re being sent the ‘guy who drops off the TV to Hugh Grant’ in a movie or ‘the newsagent’ in a TV series, because of how you look... It felt like people were going, ‘We think you’re quite good, but these are the roles that you’ll play and every now and again you might play a bubbly barrister in Judge John Deed.”

So he went away, wrote Gavin & Stacey and the calls started rolling in. “Suddenly you’re shooting the cover of Esquire and you start to think, ‘This is going to all disappear, because I’m not supposed to be here.’ If your whole life you’ve felt as if you should be here and people have said, ‘Well, we don’t think you should,’ it can feel as if it’s going to evaporate at any time. And that’s why you say, ‘Yes, I’ll do this!’ because there’s a constant feeling in your stomach that this is just a passing thing.”

But it wasn’t just his work that took a battering; it was also his character. The lovable Smithy of Gavin & Stacey quickly morphed into the annoying Corden who regularly embarrassed others, and himself, in public. There was the time he joked at the Empire Awards he was having sex with Keira Knightley, and the time he won two Baftas for Gavin & Stacey and whinged that he’d not won a third for best comedy.

Perhaps the nadir came in a spat with Patrick Stewart when he was presenting another awards ceremony. Corden admits he reacted to Stewart’s heckling badly. “Oh my God, I wish I’d just laughed it off.” Rob Brydon, who also featured in Gavin & Stacey, warned him that he was on the verge of blowing all he had achieved.

Despite the initial defensiveness, he seems much calmer today. Corden says, apart from that interlude, this is how he’s been all his life. He was brought up in High Wycombe by Salvation Army parents (his father is a Christian - book salesman, his mother a social worker) who taught him the values of decency and kindness. Yes, he says, there have been times he has let them down. He quotes the actor Bill Murray: “He said you’ve got to give anybody who becomes famous a year’s grace, because they’re being showered with so much praise it can go to their heads.

“I used to feel that if you were doing interviews, you had to be in some way obnoxious. But I don’t think that it is necessarily in my nature.”

Now, he explains, he’s more at ease with himself; more like the pre-celebrity Corden. One of the problems was when he became famous he had split up with his girlfriend of eight years and felt lost. He was often slumped in clubs in the early hours, because he didn’t feel there was anything to go home to. Not now, though. He says Julia has been a brilliant influence on him, partly because she did a proper job, for Save the Children, and was never going to be seduced by the celebrity world. Professionally, the turning point came when he played the lead in the play One Man, Two Guvnors in 2011. “It was hugely important for me because it was a play that was essentially written for me at the National Theatre. And if you’ve any aspirations to be an actor in the theatre, that’s just beyond anything you could ever comprehend.” The play transferred to Broadway, and Corden won a Tony for best actor.

He started to lose weight – some six stone over a four-year period. Now he’s down to 15 stone, but says there’s still some way to go. “I’d like to lose another two stone, but it will gradually happen; that’s the sensible way to lose weight. Those diets eating watery soups every day, you will lose loads of weight, but six months later you’ll put it back on.” Has he been offered a wider range of parts since losing weight? “I don’t know that I’d be playing such a leading role in Into the Woods if I were 21 stone.”

He says he has learnt so much from the likes of Hoffman and Streep over the past year. Not least about humility.

“They are the best kind of actors. They take the work incredibly seriously and take them- selves not seriously at all. There’s nothing worse than an actor thinking they’re changing the world.” He adored working with Hoffman andsays they spent much of the time winding each other up. Hoffman emailed him after their first day, saying, “I just want to tell you I thought you were terrible in the read-through.”

At the end of their shoot Corden told him, “Dustin, it’s been a great experience and I’m going to spread the word you’re a smashing little actor.” In America, he will be living around the corner from him. Corden has always suffered from confidence swings, and now he’s anxious about the new show in America. “It’s going to be a complete disaster,” he says. He assures me he’s not joking. “I mean that without wanting you to go, ‘No, it’s going to be great.’ I don’t see how it can be. I’m from High Wycombe. I don’t see how it can work. I haven’t done a pilot, they’ve never seen me interview anyone, it’s absurd!”

He didn’t even know he was being considered as a replacement for the Scottish comedian Craig Ferguson, so it came as a shock when he was offered the show.

Even though he was tempted to run a mile, he knew he couldn’t. But how will he distinguish himself from the other US chat shows? “We don’t just want to do chat, we want to do skits, songs and sketches. It might be the best thing I do, it might be the worst.”

At least, he says, it should bring stability to family life. In recent times, he’s been all over the place working; now at least he will be settled in LA. “For us as a family it’s a no-brainer. Shooting The Wrong Mans, I was in South Africa skyping my son on my birthday. I don’t want to be a dad who disappears to Vancouver or wherever the new tax break is, to shoot something and then come back and go on the road with a play. I don’t think it’s fair on them. I really want to be a good dad, one who knows who my kids are as people.”

Has he spoken to Piers Morgan, who was axed from his chat show on CNN? “I have. He just said, ‘Go for it and give it your best shot, but know that this is a piece of television real estate that Americans feel a sense of ownership over and they will come for you. There will be criticism, either way, whatever you do.’”

If he could last three years as Morgan did, he would regard it as a success. “Piers said, ‘I loved it so much and you will love it, and you’ve got to go for these things, however scared you are.’ ”