Football is a funny game with a strange habit of dividing families and testing loyalties. In any other circumstance, Damian Lewis would never dream of highlighting any differences he and his wife, the actress Helen McCrory, have over bringing up their children; indeed, they always show the utmost discretion in interviews, but the beautiful game brings out a rarely seen masculine tribal instinct in Lewis.
"Well we live in north London and our local team is Arsenal," says Lewis, who has two children. "And my wife, when I was filming in America – and I take great pleasure in making this public – went to the Emirates and bought my son an Arsenal strip. She doesn't even support Arsenal. I said: 'What are you playing at? You've crossed a line – a boy and father's rite of passage, going on their first trip together'."
The actor is a die-hard Liverpool fan. In his latest film, Will, he gets to play a character who loves the Merseyside club as much as he does. He plays Gareth, an absent father who promises his son, Will, that should Liverpool reach the 2005 European Cup Final in Istanbul he will take him to the match. Given his own personal allegiance, he clearly has not been coping well with the thought of his son Gulliver in an Arsenal shirt. Can Lewis bear to let his son support the local team?
"You know what, I'm in two minds about that," Lewis, 40, says. "I did say, 'He's got a birthday coming up, so I'm going to buy him a Liverpool strip as well, so he's got both'. And she said, 'Oh well, that's just confusing. You're going to play guilt trips on your son; he's going to want to wear one to please one parent and the other one to please the other parent'." Directed by the American Ellen Perry, whom Lewis describes as "dynamic and persuasive", Will is a sweet coming-of-age children's tale that features cameos from the Liverpool legends Kenny Dalglish, Steven Gerrard and Jamie Carragher.
It's no wonder that Lewis would jump at the opportunity to appear in what is a significant but far-from-leading role. He tries to claim that he's not involved with the film because it's about Liverpool, before waxing lyrical about how his side, along with Manchester United, have the "greatest romance and tradition attached to any team".
It's hard to dispute that the 2005 European Cup Final, in which Liverpool came back from three goals down, was one of the great finals in the history of football. So downbeat was Lewis at half-time that he admits that he almost missed the unlikely comeback.
"I was watching the game in a pub in Soho and I left at half-time, just going 'Oh bloody hell, this is a disaster'. I had a drink with a friend in a pub around the corner, and my friend said to me, 'Are you daft? Get back into the pub and watch the second half'. So 10 minutes into the second half I returned in time to watch them stick three goals in, in 15 minutes."
Lewis is in London on a three-day break from filming Homeland, a new series for Showtime based on the Israeli series Prisoners of War, which had its US debut earlier this month. "The reaction has been incredible," Lewis says about reviews for the show.
"It's been universally raved about so far. I'm playing a US Marine who's found in an al-Qa'ida cell after eight years and he's brought home a hero. Everyone thinks he's a hero apart from this one CIA officer, played by Claire Danes, who thinks he's been turned and is a terrorist threat.
"So, that's the set up and then it's really going to sort of unwind from there, as to whether he is or isn't; and if he is, how are they going to stop him? It's a fun premise."
Born in London and educated at Eton, Lewis has had a career in which his work on US television has been more celebrated than his British roles. "I made Band of Brothers and it just gave me a career in America. It became this cultural phenomenon and even though it was 10 years ago, it seems extremely present because people are still getting the boxsets, watching it for the 79th time. I get fan mail from the boys in Afghanistan asking me to sign boxsets; they all sit out there watching it.
"I was filming in Greece and the US Navy came in to land and they all mobbed me and said they'd watched it. Their commander had been showing it to them for inspirational exercise reasons. Young cadets at West Point were being shown this manoeuvre that Major Winters, the man I portrayed, executed the day after they landed in Normandy. And I keep reminding people, I didn't win the war, you know?"
Having appeared in several landmark TV shows, Lewis is being touted to appear in a forthcoming US drama on the Civil War, To Appomatox, although he says that is some way off and might not happen. The actor is also looking to work on more UK productions. But he admits that having tried to produce and star in the 2007 movie The Baker, directed by his brother Gareth, that "temperamentally I'm not a natural producer, because I don't have the patience".
Although his company, Picture Farm, still exists – it also produced Rise of the Planet of the Apes and Rupert Wyatt's The Escapist in 2008 – Lewis says he'll stick to acting.
With his children growing up, Lewis and McCrory needed to make a decision on where they wanted to live. "We've chosen London," he says. "Helen, you know, is a very successful actress in her own right and she has a European sensibility and she prefers it here; she does a lot of work here."
Lewis says it's likely that his next role will be on the London stage, although since he is still in talks he can't reveal what it will be. The last time he trod the boards was in 2009 for the West End debut of Keira Knightley in The Misanthrope. "There was a lot of interest in Keira being on stage, and you had to sort of get that out of the way," he says. "Some nights you could just tell that... they weren't interested in Keira. And it was great; they'd come to see the play.
"Then, other nights, it was like all 800 people had never been to the theatre before; they'd come up to town especially to see Keira, and that's quite disconcerting when you're on stage and thinking, 'I'm not sure if they're listening, they're all just staring at Keira, who's standing by the window'."
But the experience hasn't put him off working on the stage with another famous actress. "I consider it a bonus: I think the theatre is at its best when there's a sense of occasion, when there's a buzz of live theatre," he says.
'Will' is released on Friday. 'Homeland' is out in 2012