'I've never been more repulsive': Peter Sarsgaard on playing Linda Lovelace's abusive husband

He's made his name portraying ex-cons, stoners and death-row inmates. But the American actor is still not sure why he took on his latest role

It's a sunny July day in London shortly before 6pm. Peter Sarsgaard is holding the fort, in the house he and his actress wife Maggie Gyllenhaal have decamped to while she's in prep for her new movie, The Honourable Woman, a spy thriller shooting in the UK and beyond. Their eldest daughter, six-year-old Ramona, is currently running around the building with a couple of English children she's befriended. Sarsgaard smiles, telling me that he, too, used to make friends instantly when he was young; a consequence of being moved around a dozen or so times because of his father's work as an American Air Force engineer.

Sarsgaard is quite happy to be in London. It was here that the American actor shot one of his most memorable roles as the cad who dates Carey Mulligan's suburban schoolgirl in An Education. He's remained friends with Nick Hornby, who wrote the screenplay and took the actor to his first ever Premier League football match – at Hornby's beloved Arsenal. Sarsgaard favours Liverpool, however, and right now he's obsessing over the summer's transfer talk. "I'm trying to see what happens with [Luis] Suarez," he says. "The Mike Tyson of soccer!"

It's surprising to talk football with someone who spent the bulk of his high-school years in St Louis, Missouri. He's completely obsessed with the game, explaining that St Louis was "the hub of soccer in America" when he was growing up. "That's probably my favourite thing in the world, above acting," he enthuses. "My biggest hero in the world is [Liverpool captain] Steven Gerrard." He's planning to take a trip to Liverpool's Anfield stadium when the new season starts, and his eyes widen when I tell him that they face Manchester United there on 1 September.

If he does make the pilgrimage up north, it'll be interesting to see just how many people on the terraces recognise him. That's not so much a reflection on his career – he has co-starred with everyone from Tom Cruise (Knight and Day) to Harrison Ford (K-19: The Widowmaker) and Jodie Foster (Flightplan). It's more that he and his wife are the least celebrity couple you're likely to meet; so much so that in their "quiet" Brooklyn neighbourhood, they work shifts in a co-operative organic food store – Sarsgaard is a health-nut – and barely cause a second glance.

Certainly compared with his brother-in-law, Brokeback Mountain star Jake Gyllenhaal, who has romanced Kirsten Dunst, Reese Witherspoon and Taylor Swift, Sarsgaard keeps a low profile, only attending premieres for films that he or his wife feature in. He met Maggie in 2002, shortly after his one tabloidy moment – dating the burlesque dancer Dita von Teese. "I feel like Maggie and I have found a really sweet spot. We compromise a certain amount. We sell out a certain amount. We get to do what we want a certain amount. We get photographed a certain amount. We get paparazzi'd a certain amount. But none of it is too much."

Then there's the fact that Sarsgaard is a chameleon-like actor, morphing from role to role. In The Killing, the highly popular US remake of the Danish drama series, he was shaven-headed and goateed as death-row inmate Ray Seward. In his harrowing new film Lovelace, his face is obscured by a handlebar 'tache and soul-patch, all the better to play the abusive husband of the Deep Throat porn star Linda Lovelace.

He is 42 now, and – if he didn't hide behind the facial fuzz so often – quite handsome. At 5ft 11in and neither muscle-bound nor fragile-framed, it's surprising he's not had more leading-man roles. But Sarsgaard has rarely pursued the blockbuster path; and when he has – as in superhero movie Green Lantern – he's let others look daft in skin-tight leotards.

"Sometimes people say, 'Don't you want to be the guy on the poster for the huge movie?' It's not that I don't see the appeal of that, and part of me wouldn't want that, but I also know all of the things that come with it," he says. "Being the biggest movie star in the world, carrying movies every time, having the movie seen from the public's point of view as if it was made by you… you're on the poster, then you're the front-man for the movie and everybody thinks you made it."

Sarsgaard's voice – one so mellifluous it wraps you in cotton wool then rocks you to sleep – suddenly sounds animated. His career, now 18 years in, is – like his fame – in that sweet spot, so why rock the boat? He switches between film and stage (twice acting with Maggie, in productions of Chekhov's Uncle Vanya and Three Sisters), and placing himself on the A-list is not something he craves – even if his agents occasionally try to nudge him towards studio roles. "I guess it would just be about wealth, wouldn't it?" he says. "And I'm already as wealthy as I need to be. So I don't really worry about it."

The mainstay of his work is in independent movies – rising to prominence in 1999's true-life tale Boys Don't Cry, as murderous ex-con John Lotter. "I was a pretty anonymous actor then. I didn't have a publicist. And I didn't participate in the publicity for that movie. A lot of people thought they had just grabbed a guy from the Appalachians and thrown him in the movie!" Afterwards, he kept a modest profile, turning up in cult productions such as Garden State (as a pot-smoking grave-digger) and Shattered Glass (as a suspicious magazine editor). The latter won him a Golden Globe nomination – his only major awards nod to date.

Even now, Sarsgaard seems more comfortable in support – although he struggled with Lovelace, as Chuck Traynor: when he's not pimping out wife Linda (Amanda Seyfried), he's savagely beating her. "I had a deluded notion that I was playing a cool, sexy guy," he admits. Was it not like Boys Don't Cry? "No. On that one I really felt a lot wilder. I felt a lot more like a jackal! I felt very sexy, weirdly, playing John Lotter. I felt like I was just like the sheriff, y'know, and that everyone loved me. Whereas playing Chuck, I felt like everyone hated me and it made me angry… I just felt like people were going, 'Uh, Chuck is such a pig!'"

Which, let's face it, he was. Traynor pushed Lovelace into porn, and when Deep Throat unexpectedly became the cultural sensation of the early 1970s, Traynor was marginalised and the beatings got worse. "It didn't feel good to be him, and I knew going in that it wouldn't," says Sarsgaard. "I don't like the idea of my children growing up to see me playing someone like this. It's not just violence; it's violence towards women." In fact, he's at something of a loss to explain why he took the role. "I'm a curious person," he shrugs. "I've always been curious about the way other people think, especially people who think a lot differently than I do."

He sounds almost deflated by the film, that it didn't get a chance to explore anything but Traynor's aggressive side (he points out that Marilyn Chambers, the porn star he married after Lovelace, attested to him being a great guy). Was he grateful to leave the role? "Yes," he nods. "My wife was very pregnant. And I was looking forward to having nice feelings, and domestic bliss." With Maggie giving birth to their second daughter, Gloria Ray, in April last year, he got exactly that. "And I had some time to do it. I slowed down working a little bit after my child was born."

He was still able to slot in Woody Allen's new film, Blue Jasmine, which arrives here next month on the back of a fiercely strong opening in the US. It's already gaining early Oscar buzz for its star Cate Blanchett, who plays the titular, anxiety-plagued heroine. Sarsgaard plays Dwight, a diplomat she meets in San Francisco who, briefly, offers her a way out of her bleak spiral of depression. Sarsgaard admits he loved Allen's way of working – one or two takes then moving on. "I really like the feeling that there's no safety net."

Working for Allen "felt like a rite of passage", he adds, which is hardly surprising given he's lived in New York – the city in which Allen looms so large – for the past two decades, arriving there after college. Sarsgaard got his first part – as a murder victim in Dead Man Walking – in 1995; shortly afterwards, he auditioned for Allen for his musical Everyone Says I Love You, but missed out to Edward Norton. Ever since, he's been champing at the bit to work with Woody. "It's something I'd wanted to do my whole career."

The seeds of that career were planted early. While his father went from his engineering job in the Air Force to working with chemicals and then computers, Sarsgaard's family were largely artistic. His mother was a painter, his aunt a sculptor, his grandfather "an outsider artist fireman". Initially, however, he wanted to be a football player – until persistent injuries put paid to his ambitions. He amassed six concussions and quit football while studying history at St Louis's Washington University. Two weeks later, he discovered acting – performing in a gymnasium – "and realised it's my true calling", he tells me, slightly tongue-in-cheek.

It's easy to see why he ended up with his wife, who also stems from an artistic family. Aside from her brother, her parents work in the film biz – mother Naomi Foner is a screenwriter and father Stephen Gyllenhaal a director. Was he intimidated when he first met them all? "Well, Jake wasn't really a big movie star when I first started dating Maggie, so not really. And I had known so many people of that world at that point. And her parents, they are very much cinephiles and not big power-hungry movie people."

He has twice-worked with Jake – initially on Sam Mendes' 2005 Gulf War drama Jarhead. "We had a terrible time on that film. We were completely at each other's throats the entire time and I was like, 'Why am I doing this movie? I am out in the middle of nowhere, losing my mind.' A lot of the reason I did the movie was to be with him. We clearly are having the shits in the movie! And Sam was great. He put it in the film. Now we're totally close. At that time, we were ready to go at it."

That wasn't the end of tricky moments with the in-laws. Maggie's mother recently made her directorial debut with the coming-of-age drama Very Good Girls, starring Sarsgaard. He'd read the script years ago, and not really absorbed the fact that he'd have to perform a sex scene in front of her with 19-year-old Dakota Fanning (with whom he's since made upcoming eco-terrorist tale Night Moves). "It was very bizarre," he says, "Pretending to have sex with someone way too young for you in front of your mother-in-law."

He's rarely been on screen with Maggie (just a short film, 2007's High Falls), and they're not aching to get together for a movie. They are, however, both committed Democrats, and lent their faces to a video campaigning on behalf of Bradley Manning, the US soldier recently convicted for releasing 700,000 classified government documents to the WikiLeaks website – including footage of an attack by a US helicopter gunship in Iraq.

"I just don't see the way the information compromises our security," says Sarsgaard. "I think it's a cop-out and I wish the focus of the American government was more on dealing with the information that came out, like what happened on that day with those helicopters. Why did that happen? How can we prevent that from happening? When we go for a targeted killing and accidentally kill a bunch of people, how did that happen and how can we prevent that from happening? I think it's all a ruse and completely wrong to go after these whistleblowers. I think that the American government needs to look at itself rather than these other people."

'Lovelace' (18) opens on Friday. 'Blue Jasmine' (PG) is released on 27 September