CNN  — 

On Monday night, the Writers’ Guild of America officially called for a strike after failing to reach an agreement with the Alliance of Motion Picture and Television Producers.

Stephen Colbert, who taped his “Late Show” on Monday before the negotiations halted, addressed the possibility of a strike in his opening monologue when he featured a picture of all his writers, saying the show wouldn’t happen without them.

The host expressed his support for unions, and said while he hoped that a strike could be averted, “I also think that the writers’ demands are not unreasonable.”

Jimmy Kimmel, who also taped his show “Jimmy Kimmel Live!” on Monday before a strike was called, only referenced the strike tangentially when he listed the guests lined up to appear on his show for the week ahead “unless something terrible happens,” he said.

As thousands of members of the WGA prepare to begin picketing on Tuesday afternoon, hosts of the late night shows including Colbert, Kimmel, Jimmy Fallon and Seth Meyers may present the first visible manifestation that a strike has begun by airing reruns instead of a planned slate of new shows.

Members of the WGA were poised to go on strike when their current contract expires at 11:59pm PDT Monday night if the union was unable to reach a new deal with studios as the industry shifts more into streaming.

A writers’ strike could shut down production on most television shows and cause a domino effect in the wider realm of the entertainment industry, pushing back the return of many programs set for the fall.

Among the first to be impacted would be the network late night shows – ABC’s “Jimmy Kimmel Live!,” NBC’s “The Tonight Show starring Jimmy Fallon” and “Late Night with Seth Meyers,” and CBS’s “Late Show With Stephen Colbert” – as the writers those shows depend on for bits, monologues and celebrity interviews prepare to join the picket lines.

Meyers already addressed the strike last week by telling his audience that if they don’t see him in the coming days it’s due to the strike, yet he was “incredibly hopeful” an agreement can be made.

CNN’s Brian Lowry, Oliver Darcy and Lisa Respers France contributed to this report