A STUFFED parrot sways on a cobwebbed perch next to a shelf with a model steam train on top. Books on everything from The Beatles to Goya form endless towers and piles, and a battered green couch has bags instead of bums on all three seats.

Pots of paint and ink sprawl endlessly across a wooden desk like a Latin American barrio, restrained only by paint palettes, pens and scrap paper. Tony Blair's cut-out eyes gaze down from the wall at the centre of a loose collage of political photos, and everywhere there is dust, shimmering in the bright afternoon light.

It is in this tranquil clutter that cartoonist Steve Bell tears the political classes to pieces each day, serving them up in the pages of The Guardian in grotesque colour parody.

He made a monkey of George Bush, a dog of John Prescott and bonded John Major so tightly to his underpants that it arguably helped wreck his career. He made an undead aunt of Margaret Thatcher, grew breasts on David Cameron and turned Tony Blair into the mad-eyed lunatic that grinned over 1000 comment pieces.

Hannibal Lecter may have enjoyed his victims over Bach and a glass of chianti, but Steve Bell's devilry takes place to the afternoon play on Radio 4.

Describing himself as a socialistic anarchist and a libertarian, he admits this is warzone stuff as much as comedy. He calls it retaliation, aimed at ultimately destroying these people.

"They are offensive to me. You are trying to undermine them and argue with what they do. I think it has a drip-drip effect over time," Bell says in his usual cheerful tone.

He is a giant of a man, more bull than Bell, with a thick black beard and shock of hair that recalls some wrestler from a Russian circus. He is also indecently funny. The harshest words boom through great peals of laughter, and he cannot help impersonating whichever politician comes up in conversation.

"I gave Cameron his breasts last Christmas. It was a Christmas present to the world," he chortles. "He's got man boobs, but they are not just man boobs. He's got proper boobs. It's nothing to do with femaleness; it's to do with freakishness. He's got this very plausible air about him, softly spoken. He's got this funny little mouth that pouts."

Bell pushes out his lips by way of demonstration and has to hold the laughter down in his belly.

"George Bush is easy to do because he looks funny. He looks like a chimpanzee. Of course, it's unfair to monkeys to call him a monkey. What he does is noxious. He is poisonous," he says.

There are more quakes of laughter when we get to Gordon Brown. "He's got great physical attributes that you can hang a drawing on. He's got this big, big body, quite small legs, small arms and these huge jaws," he says. He roars like a bear to show what he means.

"I've watched Brown's party conference podium language. Neil Kinnock was a podium shagger. He would give the podium everything. Blair was much more of a podium stroker. With Brown, it's like he's trying to wrench it off the floor!"

Elections aside, the annual party conferences are the only time that Bell works away from his Brighton home. In the next few weeks he will be making these seaside trips in his white combi van, armed with his sketchpad to develop likenesses while he watches the politicians talk.

"At the conferences you get to see the politicians close up. The act of looking at them makes you pinpoint certain features. It's also an excuse for a piss-up," he says.

It was at Labour's 1994 get-together in Blackpool that Bell made the connection with Tony Blair that would get him through the next 13 years. By coincidence or not, it was around the same time that he had left the party over Blair's move to abolish Clause IV of the constitution, the pledge to common ownership.

Having experimented with Blair as the doe-eyed Bambi and then drawn him all teeth and ears, he knew it still was not right.

The answer came when he watched Blair's speech and noticed that his right eye twinkled while his left eye had a harder stare. The similarity, he realised, was to Margaret Thatcher, who had a peculiarity about her eyes too.

So began his manic Blair stare, which together with the ears and the teeth have paved the way to endless brutalities. With Bell admitting to probably becoming more surreal over the years, the mad eyes have been attached to everything from an electricity pylon to a door frame to a teenage hoodie.

As Blair and Bush's paths became inextricably linked over Iraq, so they appeared together in ever more savage cartoons. George Galloway dressed as Little Red Riding Hood caught them in bed together as a giant wolf-ape and terrier dog in 2003, with terrier-Blair saying: "How Dare You Call Us Wolves?"; while two years later they were lead and bass guitarist in Quid Pro Quo, singing "Shitting All Over the World". One of Bell's own favourites is from last year, picturing a blazing Blair-faced helicopter tumbling to earth with the caption, "Stable and Orderly Transition".

He denies suggestions that his own disappointment with New Labour made him attack the party more vitriolically than he attacked the Conservatives in the 1980s, however. He says: "I will admit freely that I hated Thatcher and wanted her to die. I can't say I really hated Blair that much. Once you scratched the surface there was nothing there. It was all presentation. It's shown by the fact that since he resigned, he's just disappeared."

He says that all politicians check the cartoons to see if they are in them, regardless of what they may say. Those that do not hate them make him uncomfortable, but he understands that Blair was not a fan.

Like Thatcher, however, he was too smart to complain about them. If only the same were true of John Major. Bell got the idea for depicting him with Y-fronts over his trousers following rumours that he tucked his shirt into his underpants, and although he never phoned Bell to complain personally, it was well known he hated the cartoons.

"Prescott was the other one who gave a shit. A journalist I know had been talking to him and said he had been complaining about being depicted as a dog. I am not a f***ing dog'," he laughs, mimicking Prescott's northern accent. "So of course I decided to carry on doing it."

The 56-year-old could certainly not be accused of mellowing with age. Having studied art and film at Leeds, he spent what he regards as one of the worst years of his life as an art teacher in Birmingham. "I always hated authority. I had no sense of my authority as a teacher, so I was hopeless at it," he says.

Having managed to get cartoons published in a local underground paper, he left teaching to go freelance and got his break when his Maggie's Farm strip began appearing in London's Time Out magazine in 1979.

Two years later, he was hired by The Guardian to start his If strip, and was promoted to become the paper's main editorial and political cartoonist in 1990. While he has done work for the likes of Private Eye and New Statesman in tandem at times, he has been with The Guardian for 26 years. Had he been expressing himself in words and not pictures, he admits his hard-left views would probably not have received the same space.

Although Bell regards himself as a journalist, he rarely goes to the paper's offices in London. For all his loudness and girth, he comes across as a shy man who prefers only small doses of company.

Each day without consulting the paper he develops an If strip and a main cartoon. He gets his inspiration from reading the papers, listening to the radio, watching rolling television news and looking at the latest pictures of his subjects on picture databases on his computer.

Bell's all-time favourite cartoonist is Ronald Searle, who worked for Punch and the Sunday Express in the middle of the last century. "His draughtsmanship is wonderful and he's very funny and astute," he says, adding that he also admires Beano cartoonist Leo Baxendale and David Low, who worked at London's Evening Standard and The Guardian a generation before Searle.

He has less to say about the modern crop, although he says he likes Peter Brooks of The Times and Guardian colleague Posy Simmonds.

Bell admits he would hate to be caricatured himself, since he believes a good cartoon can be more harmful than a normal drawing. And while he concedes it might not be particularly brave attacking people from his studio, he insists others are worse.

"I am still signing the piece. It's not like a blog. At least I am acknowledging my crimes," he laughs.

He denies suggestions that by focusing on politicians' characters, he trivialises the political process. "It's quite a serious business, comic art. Humour is by its very essence anarchic. You can't expect it to behave itself. A fellow cartoonist once said that cartoons don't have to make you laugh, but they do have to unsettle," he says.

Critics would say his cartoons can be far more vicious than that. What does he think of those who say he must take some responsibility for voters' disillusionment with politics?

"I say a big no to that. I may be a cynic, but it is nothing compared to the cynicism of Blair invading Iraq and saying the intelligence was wrong but was in good faith. I am using cynicism to attack a lower cynicism."

Guardian readers recently wrote to complain in droves when he spent a week depicting Brown as a big baby with dirty nappies to mock the spin that the incoming prime minister was somehow new. Some readers had been offended by the excrement, but most were saying that Brown should be given a chance and not ridiculed as soon as he took office.

The baby has since disappeared, but Bell insists he would never bow to issues of taste. The baby went because he could not see anywhere else to go with it at that point.

In general, though, he admits to having two problems with the new administration, but these too are unrelated to what the critics think. For one thing he actually quite likes the prime minister, and has generally been softer on him than his predecessors so far.

"We met at a Guardian dinner before he became chancellor. He was very interesting and funny and good to talk to. I suppose that colours your view of the man," he says.

He has also met Ed Miliband, Cabinet office secretary, and calls him a "lovely bloke". With such propensity to befriend our political rulers, this is surely another good reason for staying at home.

His other problem is that while there is plenty of visual potential in Brown's Cabinet - foreign secretary David Miliband looks like a "rather sweet monkey", international development secretary Douglas Alexander has "a sharp nose and chubby cheeks" and Ed Miliband has a "death ray stare" - he fears there are not enough personalities around.

"Sometimes I can't be bothered. This crew are so boring. It's just as important to have some kind of character on which to hang the caricature," he says, adding that he misses guys like Charles Clarke, who looked like "a big bag of testicles".

He insists he is not worried, though. The past three prime ministers and their Cabinet ministers ended up providing him with plenty of ammunition, and he has little doubt it will be the same this time.

"Gordie has got an unholy alliance going on with the Daily Mail. I don't know if he's sold his soul to editor Paul Dacre. There is a kind of Middle England posturing going on. Gordie's got to be careful there.

"I will just sit back and see what happens. The big baby might well return. In fact it could do. Why not?" he says, before dissolving into laughter once more.