Swapping Britain for France, Jarvis Cocker is living the bohemian life... when his son lets him.

It is the morning after the night before. Jarvis Cocker sits sockless in what he refers to as his "palatial residence" in Shoreditch, east London. Less than 24 hours have passed since his performance at the V festival in Staffordshire, where he danced as if his future health depended on it. The trademark jutting-elbow moves are his main form of exercise these days, along with the occasional spot of pilates. As a result of the singing, his voice is slightly shredded: it reverberates off his blue shirt, which he describes as "the blue of Cornish pottery", before sinking quietly into his corduroy trousers. He has always looked like a clash between the elderly Eric Morcambe and a starvation-era David Bowie, but in recent times this has become more apparent. Cocker is stick thin. The festivals - at least in Britain - are getting harder to endure.

"I felt sorry for the people there yesterday, not because of me inflicting my music on them, but because it was fucking freezing," he says. "My sister had been there all weekend and she looked like she'd been in a refugee camp. I admire people for staying in good spirits and enjoying themselves in those conditions because I really couldn't do it."

At least part of this, he thinks, is down to the ageing process. Many moons have passed since Cocker started Pulp, aged 15, in 1978, and since the height of the band's fame in the mid-1990s. The mere idea of meeting up in the year 2000 - the once futuristic refrain of Pulp's Disco 2000 - is now hopelessly redundant, a slice of bittersweet Britpop nostalgia. The band is currently in a state of "cryogenic suspension", which looks likely to continue for some time. On the cusp of his 44th birthday, the world looks different now for Cocker. Sliding into his fifth decade has been easy, a simple question of sleeping and waking up. But coming to terms with it is harder.

"It's a weird one," he says. "I feel more settled in myself, which is good, but you do get slightly more intimations of mortality. You realise that you have to start doing boring things like looking after yourself because physical decay starts to happen, and that's a bit of a bummer obviously. But a lot of people fall by the wayside as well. If you've still got your hair, and it's not completely grey, and you're still capable of walking upright and singing a song, then you're doing not too badly."

Only one of Cocker's bared feet is in Blighty. He spends most of his time now in Paris, where he has lived with his wife - French stylist Camille Bidault-Waddington - since 2003. The move marked a period of relative musical decline for Cocker, until his return as a solo recording artist last year. In France, his days are spent in and around his home in the ninth arrondissement; in cafés, where he ponders the mundane; in parks, where he pushes his four-year-old son, Albert, on the swings. Unlike the toddler, Cocker hasn't mastered the language yet - "which is funny, because I got a B in French at school" - but he knows enough to muddle through: "I can get the food that I want and I even managed to get my car fixed the other day, which isn't bad." In pop terms, he has been recast as the elder statesman, and now leads the life of the exiled artist, which he accepts with no regrets.

"People are always slagging off Americans for not exploring the world, but I think people in the UK can be a bit like that too," he says. "My wife suggested going to Paris because she had lived in England for a bit and I just thought, Oh, come on Jarv, be a bit adventurous, give it a shot'. I'm really glad that I did because it broadens your outlook to see how another society works."

He points to things that seem better in Paris ("It amazes me that they have strikes, and that something usually changes because of them") and things, like the Gallic sense of humour, that don't: "Maybe I just don't get it because I don't understand French well enough." The hours, he says, pass easily enough. He takes long walks, reads books, watches the weeds grow from a vantage point of relative anonymity. His lifestyle - a blend of the boring and the bohemian - would, he says, send most people to sleep.

"Sometimes I buy a baguette and walk around with it underneath my arm, and I do consume the odd croissant," he says. "I've always been fascinated by day-to-day life, probably because I can't work out how to live mine. In my experience, you usually find the most interesting things at the bottom of your garden or at the end of your street, and I've always found that more stimulating than thinking about exotic, Xanadu-type situations."

To date, Cocker's impact on French popular culture has been sporadic. He wrote lyrics for Charlotte Gainsbourg's album 5:55 last year, and collaborated with French duo Air on their recent album Pocket Symphony. In 2005, he also penned songs for the French duo The Lovers, who are based in Cocker's birth city of Sheffield. Otherwise, he has collaborated with Nancy Sinatra and Marianne Faithfull with some aplomb, and appeared as a singing wizard in the screen version of Harry Potter And The Goblet Of Fire.

Although he recorded most of the vocals for his debut solo album, Jarvis, in Les Studios de la Seine, his lyrics remain rooted in close encounters of the northern English kind. Like James Joyce, he feels that being away from certain situations makes it easier to study them closely, as was the case when he moved from Sheffield to London. Regardless of distance, his strength has always been his ability to see through the woodchip-covered walls of council houses, sifting through the rubble of broken lives to find something of worth. He is a watcher, first and foremost, but thinks that voyeurism should have its limits. He refers to a number of stinging bees in his bonnet, of which the CCTV camera is the latest. "I didn't really notice them till I came back this time," he says. "They've just crept up on us. Apparently you can go online now and access the CCTV cameras in the Shoreditch area, so instead of twitching curtains, you can actually spy on people from your computer."

Another bee in his beret is the election of the right-wing French president Nicolas Sarkozy in May, which, Cocker confirms, "left a lot of people really depressed". He recounts a visit to the park with his son, Albert, on the weekend after the elections. What started as an innocuous day out proved to be a harbinger of things to come. "We were playing football when a park keeper came and told us that we weren't allowed to kick a ball on the grass," he says. "Next thing, Albert was climbing a tree and two park keepers came and told us kids weren't allowed to climb the trees. About 10 minutes later, some kids that were surreptitiously smoking behind a bush got frogmarched out of the park by police in handcuffs. I know smoking's not good for you, but getting arrested for it is a bit much, innit?"

As one might expect, fatherhood has altered Cocker. He has said in the past that he deliberately took time off from his career after Albert's birth to become a "hands-on" dad, a decision partly based on the disappearance of his own father from his life when he was just seven. His responsibilities are the obvious ones, he says, although some still came as a surprise. "No matter what you think about yourself, or whether you have low self-esteem, a kid will make the same faces as you do, and copy the words and phrases that you use. You realise you're filling this kid's head with information and you think, shit, don't listen to me, I don't know what the hell I'm talking about'." It's a learning process, of course, but he doesn't like all of the lessons. "I've always liked living in denial of things, but when you've got kids you can't do that any more. That can be a bit daunting at first, but it's probably good for you in the end."

Cocker's habit of speaking in the second person gives even his most personal admissions the tone of brotherly advice. From anyone else's lips, it might seem patronising; from his, it feels like a show of solidarity. In his music, he has always been on the side of the underdog, whether it's asylum seekers, the unemployed, or women at the mercy of predatory men; his biggest achievement is that this has never come across as cloying. Thus, for Cocker, the rave movement was fine, to a degree, but in practice it meant "just 20,000 people standing in a field". He is not Jesus, he once sang, but "the man who stays home and does the dishes".

The iconoclastic streak prompted his stage invasion during Michael Jackson's performance at the 1996 Brit Awards, guaranteeing notoriety and applause for Cocker in equal measures. In reality, it didn't amount to much - a slightly befuddled Cocker bent over, flapping his hands, while Jackson was being hoisted in the shape of a crucifix across a stage strewn with adoring children - but it provoked the full might of Jackson's lawyers. Cocker was immediately arrested, before being cleared of any wrongdoing. In his official statement at the time, he said that his actions were "a form of protest at the way Michael Jackson sees himself as some kind of Christ-like figure with the power of healing".

The vigilante streak resurfaced on his latest album, with a diatribe aimed at the Live8 concerts in 2005. Cocker doesn't blame Bob Geldof and co for trying; instead, his ire is directed at the businessmen and leaders with whom they hoped to engage. The song, Running The World - a favourite at his recent live shows - embodies the longstanding Cocker motif that the meek will one day inherit the Earth. He will stop singing it only when the "people I refer to in a nasty way stop running the world", but realises this is a vain hope.

"When people write political songs they're usually awful, so I was really disgusted with myself for writing it," he says. "But it was something that really bugged me. People feel divorced from the political process because they think they are not listened to, and so the temptation is to buy a larger TV with a louder surround-sound system and just block the world out."

Putting Cocker in charge would be one, slightly unnerving, solution. Living outside Britain, he has had little chance to see Gordon Brown in action, but takes solace from the fact that he "can't be worse than Tony Blair". Politically, he supports the idea of more local powers for people, and suggests that London should be removed from the equation: "It's crazy really that people in London decide what goes on in the rest of the country." As a northerner, he would like to see more autonomy for the north of England, but doesn't know where the "north" would start. The thought segues neatly into Alex Salmond's proposed "conversation" on Scottish independence. "The worst thing I remember in my lifetime was when Margaret Thatcher tried out the poll tax in Scotland before introducing it in England," says Cocker. "Having been treated with that amount of disrespect, I wouldn't blame Scotland for wanting to be shot of England and to go its own way."

He could go on, but doesn't want to sound like a "grumpy old bloke". The list of things he is looking forward to includes the resumption of Albert's schooling in Paris next month ("I love him but, you know") and - warm weather provided - performing at the Connect Festival in Argyll next weekend. The fact that the event is set in the grounds of Inveraray Castle, he says, was a major factor in his decision to take part. After that, it's back to France, to writing songs, and to those difficult-to-remember verb tables. "It's like Paul McCartney said on his last album, Memory Almost Full," he says. "My hard disk is nearly full up. You start regretting all the stuff you obsessed over in your teenage years because you find that you still know all the catalogue numbers to Jam singles. You think, ooh, I could have given over that valuable storage space to something actually useful, like where my keys are'."