Gerald Scarfe with one of recent caricatures

Consider the deep-rooted respect accorded to the likes of Gerald Scarfe, David Frost and the late Peter Cook - faces who were in the vanguard of the 1960s political satire boom.

Scarfe recently recalled how, in the conformist climate of the 1950s and early 60s, critics slated his lampooning illustrations as "obscene and grotesque".

Even Private Eye, a magazine whose raison d'�tre has always been to laugh in the face of the establishment, baulked at one of Scarfe's cartoons which portrayed in graphic detail how Harold Wilson was in the grasp of American president Lyndon Johnson.

Thirty years later and Scarfe was commissioned to build a series of installations for the Millennium Dome, a project that was synonymous with authority and government control.

In a sense Spitting Image made me

Michael Heseltine

Neither is the "shock" and "outrage" that greeted the broadcast of Morris's programme on Channel 4, Brass Eye, by any means a new trend.

A recent exhibition of the works of 18th Century caricaturist James Gillray at the Tate was a reminder of how, almost by its nature, satire must sail close to the wind.

Gillray's cartoons scathingly ridiculed society figures and statesmen alike. Politicians were pictured in the act of relieving themselves, the wealthy and the titled were depicted groping their mistresses.

Curiously though, the very people who should be offended the most - a satire's subjects - are sometimes its biggest fans.

Heseltine owes a debt to his Spitting Image puppet

Gillray's images were eagerly sought by some of their subjects and, more recently, Michael Heseltine has said he owes a debt of honour to Spitting Image, the TV show that portrayed him as a crazed puppet of Tarzan swinging on vines.

"In a sense Spitting Image made me," Heseltine has said.

The fragile nature of the human ego is such that these cases tend to be the exception. But when it comes to making enemies, there can be a thin line between enraging the subject and offending society at large.

Rory Bremner, widely held to be Britain's foremost political satirist of the moment, appeared to cross that divide last year when he decided to resurrect the memory of late Princess Diana for one of his shows.

Portraying the princess as a ghost counselling Prime Minister Tony Blair was a step too far for some.

Diana depiction

"Rory's sick joke? By depicting the ghost of Diana, Britain's top impressionist may have finally gone too far," ran a headline in the Daily Mail, the newspaper that has been most vociferous in condemning Morris's Brass Eye in recent days.

Yet only last month the Daily Mail carried a column by writer Allan Massie affirming the tightrope that a satirist must walk.

"Satire aims to wound, to draw blood. Good satire demands to be taken very seriously. It is fuelled by anger and contempt," wrote Massie.

Morris might well agree. But if he is found guilty of overstepping the boundaries of taste and decency by the press it could be because his primary target for ridicule in the Brass Eye programme was not politicians or even paedophiles, but the media itself.