We have practically no agreement at all. I think my job is to come along and draw things and see what happens.

Martin Rowson

In what must rank as a brave - if not foolhardy - move, the mayor of London, Ken Livingstone, has appointed Martin Rowson to take on the job. Should Mr Livingstone be expecting a cosy comic book full of wizard japes and happy endings, he's certain to be disappointed.

No Mr Nice Guy

Rowson, whose work is published in the Guardian, the Independent on Sunday, the Scotsman and Tribune, displays a level of viciousness in the style and content of his cartoons that is rarely exceeded.

Rowson: "I'm going to bite the hand that feeds me"

His manifesto for his new job? No easy rides, no cosy gentleman's' agreements to be nice to anyone.

His role, he told BBC News Online, would be primarily to portray the mayor and the Greater London Authority in cartoons, for the princely sum of one pint of London Pride a year.

But he also wants "to bring in a satirical slant from the inside".

"One of the things I and most other cartoonists beef on all the time is that we are not taken seriously enough, both culturally and politically. It's a fact that people will look at newspaper cartoons and form their judgments of people and policies and politicians.

In tents

"And yet, though politicians will always claim: 'Oh that's terribly funny and I've got very broad shoulders', they try for their own sanity not to take cartoons very seriously. This is the first time a cartoonist has been invited inside the loop."

Rowson's take on his new generous patron

Adapting Lyndon B Johnson's famous line about relative merits of standing inside or outside tents, Rowson says he will be on the inside, doing what he does outside but over his own shoes.

"It's part of the business of a cartoonist to be an outsider and then to be invited in to the banqueting hall and to be offered the fingers to lick by the king because you're playing the role of the court jester. Then you have to bite the bastard's fingers off and keep gnawing until you get to his elbow."

Cartoon expert Dr Nick Hiley of the University of Kent's Centre for the Study of Cartoons and Caricature likens the role to the person employed to stand behind Caesar to keep reminding him of his mortality.

I am largely pursuing a political agenda. And one way I do that is to depict the people I depict in a way that will make people feel the less of them

"It's interesting that it's Rowson because he's part of a much longer tradition in cartooning and caricature, reaching back to the age of Hogarth and Gillray and he acknowledges that in his work," he said.

Rowson's intricate drawings also had a flavour of the 18th century about them, he said. You could almost imagine seeing them in a print-seller's window rather than a newspaper.

So what's in it for Ken?

But the prospect of someone who has been so critical of the establishment now working from the inside begs the question of what's in it for Ken Livingstone?

There is a strange feeling, says Nick Hiley, that cartoonists and politicians need each other and flatter each other.

William Hague under attack from all sides

However nasty cartoonists are about politicians - and there are some very pointed cartoons indeed - cartoonists often find the targets of their attacks on the phone, ringing to ask if they can buy the originals.

"People like Ralph Steadman have actually turned against the whole idea of political cartooning, because they believe that, however vicious, it's generally a form of flattery to politicians."

So what does Rowson think are the mayor's motives?

"I think Ken rather likes the idea of being seen differently from most politicians, likes the idea of playing it a bit differently.

"And also one of his major gambits as a political character is to be seen to be someone who doesn't take himself too seriously, isn't too pompous and likes a bit of a laugh.

"I think he's a consummately brilliant politician, because he doesn't appear to be a politician. But I do think that like any other politician he is driven by personal ambition and the lust for power."

It could be a risky business, says Nick Hiley.

"It's amazing the way public feelings about politicians can be conveyed by cartoons about them - just think of John Major in his underpants, as drawn by Steve Bell. He's going to go down in history with his underpants outside his trousers.

"It could always be that Ken is hoping to be immortalised in this way - even if he's attacked he will go down in history in some way."