Dough! Make it $360,000 an episode or we quit the series, say Springfield Six

Hollywood's newspaper of record, Variety, once called The Simpsons America's "dysfunctional First Family". And clearly the dysfunction is contagious, because several leading cast members have refused to show up for work in the past few weeks over a salary dispute.

Hollywood's newspaper of record, Variety, once called The Simpsons America's "dysfunctional First Family". And clearly the dysfunction is contagious, because several leading cast members have refused to show up for work in the past few weeks over a salary dispute.

Dan Castellaneta, who plays Homer, has gone Awol, and so too have Nancy Cartwright (Bart), Julie Kavner (Marge), Yeardley Smith (Lisa), and the multi-talented, multiple-role players Hank Azaria and Harry Shearer.

Their bottom line is that they have been at this for 15 seasons - next year's would be the 16th - and they want a larger slice of The Simpsons' considerable financial pie to make it worth their while to continue.

They want a salary rise from $125,000 (£67,000) to $360,000 per episode for the 22-episode season, Variety says. That, the actors say, is far from unreasonable, given that The Simpsons is a billion-dollar global cult phenomenon - broadcast in languages from Swahili to Albanian - and that their famously flexible voice talents are a large part of the secret of its success.

So far, they have failed to appear for two read-throughs of next season's scripts. That, in turn, has put production on hold, because the animators cannot get to work until they have a finished voice tape allowing them to synchronise the lip movements and other interactions of the characters.

With the clock ticking, the negotiations can only get more interesting from here. Twentieth Century Fox, the Rupert Murdoch-owned television company reaping the benefits of the world's most enduring animated sitcom, might not like what is going on, but it also that it has been in a very similar situation before, and ended up losing.

In 1998, when the principal players were being paid just $30,000 an episode, they staged a similar walkout. Fox went as far as hiring casting directors in five cities to seek replacements for them, only to back down when it became obvious that they risked strangling the very baby they were trying to save.

Since then, salary negotiations have been largely amicable. The most recent deal covering seasons 13, 14 and 15 was hammered out with little acrimony.

Fox knows The Simpsons is a sure-fire comedy in a television landscape desperately short of sure-fire comedies. As one critic wrote when the show marked its 300th episode in February: "It's about the only network show that can be depended on for a few laugh-out-loud moments week after week, the one show that employs stunt casting that actually works and, perhaps most importantly, never gives in to the PC police."

Now everything is different. Agents and managers representing the actors have spent months trying to negotiate a new deal. Could this be the beginning of the end of the inept antics of Springfield's finest? And what will this do to the long-cherished project of turning The Simpsons into a full-length feature film? Previous instances of high-profile salary disputes suggest it might be, if not immediately, then soon. Almost every long-running hit show, from Seinfeld to Frasier to the NBC audience favourite Everybody Loves Raymond, tends to follow a pattern whereby the actors' salaries shoot ever higher even as the ratings begin to plateau or fall.

Sooner or later, someone starts to ask if the ever-increasing outlays are really worth it. Sooner or later, the new episodes stop making even a fraction of money earned from syndicated reruns of earlier seasons. And sooner or later, some executive honcho pulls the plug.

Thus it was that Kelsey Grammer, who played Frasier Crane for 20 years, first on Cheers and then on Frasier, generated headlines a couple of years ago by becoming the first television star to earn $1m per episode. Not coincidentally, Frasier has just gone off the air in the United States.

With Seinfeld, whose nine-year run ended in 1998, the issue was less about Jerry Seinfeld than it was about his three co-stars, Julia Louis Dreyfuss, Jason Alexander and Michael Richards, who resented - and continue to resent - being key components of the show's success but earning only a fraction of the money because Mr Seinfeld was co-creator and a senior producer on the show.

They clawed their way to $600,000 per episode in 1997, having threatened to take the show off the air if they were not given their due. Seinfeld ended 12 months later.

From the actors' point of view, the motivation is often to take what they can from an ageing show while it is still on the air, not least because television actors find it notoriously hard to find other work once they have been closely identified with one part in a hit show.

That is less of a problem with The Simpsons, because the actors use only their voices. Even they are unlikely to find such high-paying work again. Some, including Mr Shearer and Mr Azaria, rely on the money from The Simpsons to subsidise much less well-paid work in theatre or radio.

Fox executives appear to resent the actors' attitude. "They already have the deal of a lifetime," one said. In 1981, an actress called Suzanne Somers walked out of the sitcom Three's Company because she felt underpaid. The show continued nicely for several years without her. Ms Somers was reduced to promoting the Thighmaster on home shopping channels.

Who plays who in The Simpsons

Nancy Cartwright (Bart)

Has played voice parts in many films over the years, including Who Framed Roger Rabbit and Twilight Zone, The Movie in 1983.

When she first auditioned for The Simpsons, she was rehearsing for the voice of Lisa, not Bart. Aged 44.

Dan Castellaneta (Homer, Krusty the clown)

A vegetarian who doesn't drink, Castellaneta, 45, came to fame through The Simpsons. He invented Homer's trademark phrase "D'oh", now in the Oxford English dictionary. The phrase appears as "annoyed grunt" in Simpsons scripts.

Julie Kavner (Marge)

The part of Brenda in the sitcom Rhoda was written for her. Film roles include National Lampoon Goes to the Movies and Hannah and Her Sisters, the first of her collaborations with Woody Allen. (Others include Deconstructing Harry.) Aged 53.

Yeardley Smith (Lisa)

Played Marlene in the television series Dharma and Greg. Also appeared in Billy Crystal's film City Slickers in 1991 and in As Good as it Gets, with Jack Nicholson and Helen Hunt. Her father was an obituary writer for the Washington Post. Aged 39.

Hank Azaria (Moe, plus several others, including Chief Wiggum)

Was briefly married to Helen Hunt until their divorce in 2000. Based the voice of Moe the bartender on Al Pacino. Played alongside Robin Williams and Gene Hackman in The Birdcage in 1996. Aged 39.

Harry Shearer (Montgomery Burns, Ned Flanders)

First appeared in Abbott and Costello go to Mars (1953). Best known for Saturday Night Live gigs and the film This is Spinal Tap (1984) where he played Derek Smalls. Plays 17 Simpsons characters. Aged 60.