LONDON'S Battersea Arts Centre. The ornate entrance hall has been converted into a makeshift art gallery for the final scene of new British comedy The All Together. The art' on display consists of several stuffed-and-mounted animals, all of which appear to have been practising various positions from the Kama Sutra just as the taxidermist got going. Just as I'm hoping nobody calls the RSPCA, I'm roped into being an extra, one of two dozen or so guests at the opening night for this bestial exhibition.

I skulk at the back, drink in hand, just as Martin Freeman arrives, our leading man. It's the last night of the shoot, and the clock is creeping towards 11pm. "I've certainly never done anything that tight before," Freeman remarks later. "It really has been a proper race."

The scene tonight sees Freeman's character Chris, a television producer, arrive at the gallery where his hapless neighbour Bob Music (Velibor Topic) is exhibiting these unusual statues. Dressed in a suit-and-tie, Freeman loiters around, hands in pockets for a while, as he waits for the next shot to be set up. Looking like he could melt away into the crowd at any second, he seems less bewildered or quietly desperate than Tim Canterbury, the character that made him famous, from Ricky Gervais' sitcom The Office.

In real life he's more like a younger, better-looking version of Hancock. Amusingly, the innocence his rather cherubic features and mop of brown hair projects is entirely undermined by the fact he swears like a trooper. "Every interview I do," he groans, "it sounds like I've got Tourette Syndrome."

It's close to midnight when Freeman manages to find some time to sit down and chat, at the back of a dusty hall, adjacent to the set. Nearby is his real-life girlfriend Amanda Abbington, who plays Sarah, a student that Chris - after much goading - plucks up the courage to ask out on a date. He waves to her, and shoots across a cheeky grin. It was Abbington - whom Freeman met on the 2001 TV drama Men Only - that first read the script for The All Together.

"Amanda said, I think you'll really like this. You'll be good in it'," recalls Freeman. They certainly share a capacity to rant. Chris, who harbours designs on writing a screenplay and hopes to sell his house to fund it, opens the film with a monologue railing against formulaic British films. As a scene, it couldn't be better tailored to Freeman's ability to go off on one.

With Chris coming into contact with everyone from pain-in-the-ass presenters to vomit-covered gangsters, the comedy is as farcical as it is twisted. But there's evidently a lot of love in the room for this low-budget effort. Not least because writer-director Gavin Claxton has his house on the line to fund the film, a decisive action that Freeman evidently admires.

"He believes in it, which was one of the reasons I wanted to get involved," he says, "I'm very taken with people who speak truthfully, from the heart, and I liked his voice in the film. I thought it was good; it wasn't written for a demographic or by committee. It wasn't just about, How can we get a tax break?'"

When we first met, it was March 2005, just a few weeks before Freeman was due to hit the screens as Douglas Adams' hapless intergalactic hero Arthur Dent in the big-screen version of The Hitchhiker's Guide to the Galaxy. I remember asking him about how he felt about the prospect of impending fame. "I keep my head down and try not become famous as much as I can," he said. "It is to be avoided for me at all costs. Hence not going to any premiere, party or awards thing. I've just been Tim f**king Canterbury and I don't want to be Arthur Dent for the next 10 years. I have different ambitions. I want to be an actor and not just a character. My job is an actor, not a famous person."

Almost two years on, Freeman and I get a chance to catch up. It's been a productive time for him. After appearing again with Abbington on BBC1 sitcom The Robinsons, he has played it smart. There was Confetti, a hit-and-miss mock-documentary about three couples competing to stage an original wedding, in which Freeman and Spaced star Jessica Stevenson stole the show with their MGM-musical style ceremony. A strong supporting role as Jude Law's architect colleague in Breaking And Entering proved he could ride out even the most cringeworthy of scripts. And a cameo in Hot Fuzz, alongside his old friend Simon Pegg, showed he hadn't forgotten his comedy roots.

Best of all, Freeman had escaped the pigeonholing he feared. Hitchhiker's took a respectable $51 million in the US alone, even going to number one in the box office charts on its opening weekend, but it wasn't enough for a sequel to be rushed into production. This, he says, "is one of the good things - forgive me for saying it - for it not being the commercial success we hoped it would be".

Freeman evidently has an aversion to all things Hollywood. He has no desire to make, as he puts it, a "f**king lunchbox money-making scheme". In other words, a franchise designed simply to peddle merchandise. "I'm not relaxed enough in any portion of life to say, Let's just do the franchise'," he says. "I've got too much anger in me."

No proof is needed of this. Several times, Freeman launches into expletive-driven rants about the world of filmmaking. "I'm very self-critical and I have a certain take on why we make art, and I make no apology at all for seeing what I'm involved in as art. I have no interest in the industry or the business," he says, building up a head of steam. "We all know what the industry is full of - whether it's music or film. It's full of f**king people who didn't have the talent or the foresight or the balls to go into it themselves, so they ended up being f**king bean counters. So I don't want to be complimented by them. I don't want to be flattered by them."

He stops, takes a breath and cracks a smile. "Said Martin, as he never worked again."

But there's much chance of that. At this year's Sundance Film Festival, Freeman featured in two films. In Justin Theroux's romantic comedy Dedication, he plays a small role as Mandy Moore's ex-boyfriend "who tries to woo her again with not altogether honest intentions", as he explains. He liked the fact that he was able to play around with audience expectations of him as "the cute lovelorn guy", built up from his days as Tim. It's clear he's sick of being called an Everyman'.

"What if I wanted to play a paedophile, a rapist or Stalin?" he asks. "I want to do all those things, and why not?" While there's no doubting he could, Freeman still has much work to do before he will stop overhearing members of the public saying It's just like Tim from The Office, but in a different costume', as he has done. "You do sometimes wonder what you have to do," he cries. "Maybe become a black woman!"

I ask if he got this Tim From The Office accusation after playing Arthur Dent. "I get a lot of it from everything," he says, exasperated. He then begins another entertaining - though admittedly well-thought out - rant about how, as an actor taking on a part, you can't literally become someone else and therefore will always shape every role with elements of your own personality.

"It's a kind of a cab driver's response," he continues. "Oh yeah, Ray Winstone - he's the same in everything.' Well, you be that f**king good and then get back to me. I don't care if people are similar. Do I care that George Clooney has never played an Irish dwarf? I don't give a shit! He's great. I'm not saying I'm great, but I'm working on it. I'm working on doing work that I like." His other new film, The Good Night, is hardly going to help, mind you. Set in New York, Freeman plays Gary, a former pop star who gradually begins to undergo a mid-life crisis. Much of this seems to revolve around fantasising about a model (Penelope Cruz) who haunts his dreams. Directed by Jake Paltrow, and featuring his more famous sister Gwyneth (as Gary's long-suffering girlfriend), if Freeman is still left playing the Everyman, at least he's now doing so alongside Hollywood A-list stars.

I put it to him that the film will certainly broaden his international appeal and he shrugs. "If it means more people know you, then great. But, I don't know, man" He tells me he's proud of the film, that the key question in his mind whenever he takes a role is, Can I stand by why I did the film?'. "It's a big thing for me," he adds, "keeping integrity." Given that in the film Gary's career has been reduced to penning commercial jingles, does Freeman ever fear he may start selling out one day? "It's always possible and to be honest, I'm always on guard against it," he says.

"I need to know why I'm doing something. That I'm not just taking the money and running, which I can pride myself on not doing. I don't do that. Which is why I do films like The All Together, because I like it. Which is why I don't do many of things that would, on paper, see my career and my bank balance do so much better. Of course I don't want to be poor. But I'm not interested in it over and above why I wanted to be an actor in the first place. What I don't want is success or money at all costs."

It's tempting to think that Freeman's background has helped contribute to these noble sentiments. Born in Aldershot in 1971, the youngest of five, he was evidently a party to a creative environment from an early age. "My mum's quite classy," he says. "She likes books and art and stuff." His older brother, Tim, was in Eighties art-pop group Frazier Chorus; another brother, Jamie, is a musician and website designer; and his cousin, Ben Norris, is a stand-up comic. Freeman is also a big music nut, from his teenage days when he was into punk to listening to the likes of Public Enemy, De La Soul and The Jungle Brothers later. He even rapped in a band for a bit. So, did he consider his family artistic when he was growing up? "Yeah, I would say so," he nods. "It is not like we are all patrons of the National Theatre, but we can all paint or draw or play music."

Catholic-raised, Freeman's early life was not easy, by the sounds of it. His mother Philomena, a housewife, and father Geoffrey, a chief petty officer in the navy, divorced when he was young. He went to live with his father, who then died when Freeman was just seven. He returned to his mother and stepfather James, who ran pubs. Eventually the family settled in Teddington. A sickly child, Freeman suffered from both asthma and a recurring hip problem. "I had to lay off the sport - cold turkey from football. I was never destined to be Paul Scholes, but like most boys of a certain age, I liked to play football. That was purgatory for me.

Freeman also carried on playing another sport - squash. He was good, too. Part of the British national squash squad from the age of nine to 14, he regularly travelled the country and competed in tournaments. For those five years he thought he was going to play the game professionally, then he just "fell out of love with it". He shoots me a knowing wink. "By now my career would be well over."

He started acting at Teddington Youth Theatre, went on to study drama at Central in London's Swiss Cottage and his first job was for the National Theatre, taking small roles in plays such as Volpone. "I've never really seen myself as a comedian," he says, all too aware that his successes to date have seen him cast as the funnyman - whether it be The Office or taking on Sacha Baron-Cohen in Ali G Indahouse.

Yet if The Office cast him for all eternity as the Everyman, Freeman is fighting it for all he's worth. If The Good Night won't exactly help him in this quest, he's just finished playing Rembrandt for Peter Greenaway, the British director behind such Eighties arthouse classics as The Draughtsman's Contract and The Cook, The Thief, His Wife And Her Lover. His new film, Nightwatching, weaves a fictional story around Rembrandt's painting The Nightwatch.

"It's a love story, and it's all about passion, desire, money and murder," says Freeman, excitedly. "It's got all those things that pretty much every film in your DVD collection you love has got." He calls Greenaway "an extremely clever and very weird man". Uncompromising, too, I suggest. "Infuriatingly so, at times. It was not an easy experience."

For the next few months at least, Freeman intends to stick around in Britain. "I've got things coming out this year, so I need to keep a fairly clear deck so I can support them," he says. His main project on the horizon is The Last Laugh, a play he did at the beginning of the year with Roger Lloyd-Pack that is due to transfer to the West End. A two-hander adapted from an original play by Koki Mitani, "it's a comedy about comedy and censorship", says Freeman, who stars as a playwright trying to get his latest work past the government censor in an unspecified country "but with a whiff of the Eastern bloc".

But his main reason for hanging around in London for the foreseeable is more domestic: he and Abbington recently became parents - to a baby boy named Joseph.

I ask if he'd like to work with Abbington again. "Def-o," he chirps. "I do like working with her. It's always nice when we do work together." Much of their work to date - The Robinsons, Men Only and The Debt, a thriller with Warren Clarke - has been for television, but Freeman is looking out for something bigger.

"I'm really hoping and waiting for the time we can do something big together, and have more scenes together. I mean, she's one of my favourite actors. I think she's f**king great. I love working with her and hopefully I will again. I would like to do something major with her. That would be nice."

He seems to have no qualms about being seen as a screen couple. "It's not like we're Ken and Em," he chuckles. "Obviously, it could become self-indulgent, but we're not well-known enough for that to happen."

And if he has his way, they won't be.

The All Together opens on May 11. The Good Night is released later this year