The US screenwriters' union has called a strike starting next Monday to demand a fair share in royalty payments from DVDs and new media sales.
Late-night TV chat shows seem likely to be the first victims of a strike by the US screenwriters' union, which has been called over royalty payments.
About 12,000 members of the Writers Guild of America are being asked to cease work and set up picket lines from 0001 local time (0701 GMT).
The Writers Guild of America has asked its 12,000 members to stop working and set up picket lines from Monday.
The last such action, nearly 20 years ago, lasted 22 weeks and disrupted the autumn television season.
It wants more cash for work which goes on "new" media such as DVDs or online.
The studios and the union will meet on Sunday morning for last-ditch talks.
Shows hosted by stars such as Jay Leno, David Letterman and Jon Stewart are expected to stop almost immediately as they rely on a supply of topical jokes.
The Alliance of Motion Picture and Television Producers (AMPTP) said the talks to try to avert the strike would take place at a neutral venue.
They call it the toughest time for comedy writing since those three weeks back in the 1990s when Bill Clinton stopped dating Talk show host Jay Leno
'DVD roadblock'
It was anticipated NBC would broadcast repeats of Leno's programme, The Tonight Show, plus Late Night with Conan O'Brien and Saturday Night Live from Monday if the walkout went ahead, the Hollywood Reporter said.
The strike deadline was issued by WGA leaders on Friday on the recommendation of their negotiators, after talks with producers broke down.
It also said old episodes of The Daily Show and The Colbert Report would be screened under contingency plans by the Comedy Central channel.
There is no backlog of scripts Amy PoehlerCast member on Saturday Night Live
But as yet it was unclear what other networks intended to do, it added.
"The Writers Guilds will go on strike Monday, November 5th at 1201 AM," a statement said.
Leno made a quip about the strike on-air on Friday, saying: "They call it the toughest time for comedy writing since those three weeks back in the 1990s when Bill Clinton stopped dating. Remember that?"
"At that time, all Guild-covered work under the MBA [Minimum Basic Agreement] must cease."
Filling the gaps
Talks between WGA negotiators and the AMPTP broke down on Wednesday, hours before an existing agreement was due to expire.
The last such action, in 1988, disrupted the autumn television season.
Writers are demanding an increase in the fees they receive when their work is reproduced on DVDs, and a fair share of revenue derived from content on the internet, mobile phones and other electronic devices.
At that time, Letterman was host of NBC's Late Night, and his programme was taken off-air at first. It did return before the end of the 22-week strike, however, but many other shows remained unbroadcast.
Producers reject their demands as unworkable.
Satirical show The Colbert Report is set to be among the casualtiesIt is anticipated daytime TV output, such as chat shows and soap operas, would be next to suffer if this month's walkout goes ahead. These series are typically recorded about a week in advance of transmission.
Michael Winship, president of the WGA on the East Coast, said there was still time for producers to avoid the action.
The strike would not immediately impact production of film or primetime TV programmes, the Associated Press reported.
"We urge the studios to come back and bargain fairly," he said after the strike announcement.
This was because most movie studios had already kept aside a number of scripts, and many high-profile TV dramas and comedies had enough scripts or completed shows to last until early next year.
Nick Counter, president of the AMPTP, said the studios were ready to meet and finish negotiations over the weekend.
But then Hollywood analysts do expect the supply of shows such as Desperate Housewives, Ugly Betty and CSI to fizzle out, and many writers fear the TV networks will turn to additional repeats and reality programmes to fill the resulting gaps.
Earlier, Mr Counter had said no progress was possible at the talks "for overriding business reasons" as long as writers insisted on increasing royalties from DVD sales.
Further negotiations
The studios and the union will meet on Sunday morning for last-ditch talks at a neutral venue.
Writers are demanding an increase in the fees they receive when their work is reproduced on DVDs, and a better share of revenue derived from content on the internet, mobile phones and other electronic devices.
Writers have been taking their protest to the streets of New YorkBut producers have rejected their demands as unworkable.
This led to Letterman calling producers "cowards, cutthroats and weasels" on his CBS show on Thursday.
Michael Winship, president of the WGA on the East Coast, said there was still time to prevent the walkout, adding: "We urge the studios to come back and bargain fairly."
Nick Counter, president of the Alliance of Motion Picture and Television Producers, said the studios were ready to meet and finish negotiations over the weekend.
Earlier, Mr Counter had said no progress was possible "for overriding business reasons" as long as writers insisted on increasing royalties from DVD sales.
"The DVD issue is a roadblock to these negotiations," he added.
"The DVD issue is a roadblock to these negotiations," he added.
Gradual effect
Some of the most popular shows on US television could be forced off the air if writers go ahead with the strike.
Writers have been taking their protest to the street already
Late-night talk shows are expected to stop almost immediately since they rely on a daily supply of topical jokes.
Television host David Letterman described producers as "cowards, cutthroats and weasels" on his CBS show on Thursday.
The comedy show Saturday Night Live could also suffer immediately.
"Boom - our show just shuts down," Amy Poehler, a member of the cast, told LA-based newspaper Daily Variety.
"It's just done. There is no backlog of scripts."
While it could be months before the TV networks run out of programmes that have already been made, Hollywood analysts expect the supply of shows such as Desperate Housewives, Ugly Betty and CSI to fizzle out by next spring.
Many writers fear the TV networks will simply turn to more repeats and reality programmes to fill the gap left by scripted shows.
Are you a Hollywood writer affected by this story? Send us your comments by filling out the form below.
Are you a Hollywood writer affected by this story? Send us your comments by filling out the form below.
I have screenplays registered with the Writer's Guild of America West, so I can have the additional protection when pushing my work overseas, mainly in Japan as a backdoor, so I can get into the USA. I think the MBA (Minimum Usage Agreement) is a poor man's farce, plus what a writer has to do just to achieve entry into the Guild is nearly beyond belief. But on the other side, the amount of cut-throat dishonesty that exists among leading industry producers is much worse. Without the Guild's protection we really would have nothing. Given the global economy in which all mediums compete with everything, a larger royalty belongs to the writers. And let's not forget the overcost of for-profit health care in America that the Guild provides to writers as a benefit. This is always left out of the equation. It's not a "benefit", when in reality we are fighting for our lives against a for-profit health care system that's against all of us. I fully support all the writers' efforts as one. But as a free agent, I will continue.Alan Colosi, Boston, Ma
I have screenplays registered with the Writer's Guild of America West, so I can have the additional protection when pushing my work overseas, mainly in Japan as a backdoor, so I can get into the USA. I think the MBA (Minimum Usage Agreement) is a poor man's farce, plus what a writer has to do just to achieve entry into the Guild is nearly beyond belief. But on the other side, the amount of cut-throat dishonesty that exists among leading industry producers is much worse. Without the Guild's protection we really would have nothing. Given the global economy in which all mediums compete with everything, a larger royalty belongs to the writers. And let's not forget the overcost of for-profit health care in America that the Guild provides to writers as a benefit. This is always left out of the equation. It's not a "benefit", when in reality we are fighting for our lives against a for-profit health care system that's against all of us. I fully support all the writers' efforts as one. But as a free agent, I will continue.Alan Colosi, Boston, Massachusetts
As one of the very few British members of the Writers Guild of America (West), I'm saddened by the Producers' attitude in this negotiation. This is a New Century, and a different world we live in. The Internet has helped change the fabric of our existence, and the WGA Membership are seriously taking new distribution methods for our created material into account now...our livelihoods depend upon it. I believe our Guild have the grim resolve to push this unfortunate strike, until we're finally given a fair piece of the pie we're so instrumental in baking. Be warned, Mr Counter: we're unlikely to cave as readily today as we did nearly two decades ago... Peter Briggs, Los Angeles, California & London, England
As one of the very few British members of the Writers Guild of America (West), I'm saddened by the Producers' attitude in this negotiation. This is a New Century, and a different world we live in. The Internet has helped change the fabric of our existence, and the WGA Membership are seriously taking new distribution methods for our created material into account now...our livelihoods depend upon it. I believe our Guild have the grim resolve to push this unfortunate strike, until we're finally given a fair piece of the pie we're so instrumental in baking. Be warned, Mr Counter: we're unlikely to cave as readily today as we did nearly two decades ago... Peter Briggs, Los Angeles, California & London, UK
I have been writing these worthless scripts for years. I am actually pleased there will be a strike. Not necessarily for better royalties. I think it will give people a chance to reflect upon the mind-numbing quality of what we are churning out. Andrew Johnston, Evreeware, California
This isn't just about the writers, it affects everyone in this town... from the make-up artists to the production assistants just starting out. People think that it's just rich writers being affected, but they are way off. This town thrives on this industry and the fact that the rich execs wont pay a fair rate to those that deserve it blows my mind. The big issue here is that this is just the start. The contracts with the Directors Guild (DGA) and Screen Actors Guild (SAG) will also be facing this same issue in a few months, so they better figure out something... quick!David Tobin, Hollywood, California
The bright side is that maybe unknown writers like me will be able to get their work noticed out of sheer desperation. Hopefully they will find the talented, unnoticed writers that were unable to get their scripts noticed.Daniel Tokle, Lakewood, Callifornia
I applaud David Letterman's description of the producers as "cowards, cutthroats and weasels". But he *was* reading it off the autocue.PedroC, UK
I am a British writer who also works in LA and am a member of the WGA. It may seem to people outside the industry that it's one priviliged group whingeing at another. Apart from the fact that many, if not most, writers struggle to make a living, what's at stake is an erosion of the fundamental right to be paid fairly for the work you do. To put "fair share" into context: the writer's royalty from a $10 DVD is four cents. The studios have been trying to reduce this!Mark Burton, Reading, UK