London, Jul 14 (IANS): The cast of Christopher Nolan's new film 'Oppenheimer', including the likes of Cillian Murphy, Emily Blunt, Matt Damon and Sir Kenneth Branagh, left its London premiere early to "go and write their picket signs" ahead of a strike by Hollywood's largest actors' union.

Cillian Murphy was joined by Emily Blunt, Florence Pugh, Matt Damon and Rami Malek as they walked the red carpet an hour earlier than scheduled in order to join the walkout, mirror.co.uk reported.

The walkout came after the US actors union Screen Actors Guild-American Federation of Television and Radio Artists (SAG-AFTRA) announced its first major members strike in over 40 years, after a deadline to reach a deal ended.

The reasons for the strike include issues such as the use of unregulated AI as well as the effects of the rise of streaming services on pay.

Just moments into the 'Oppenheimer' event at the Odeon in Leicester Square, director Christopher Nolan told the audience that the star-studded line-up had left. Nolan said: "I have to acknowledge the work of our incredible cast, led by Cillian Murphy. You've seen them here earlier on the red carpet. Unfortunately, they're off to write their picket signs for what we believe to be an imminent strike by SAG, joining one of my guilds, the Writers Guild, in the struggle for fair wages for working members of the unions, and we support them."

SAG-AFTRA is an American union representing around 160,000 film and television actors. Before the movie started inside the cinema, Matt Damon explained that he and his co-stars were walking out in "solidarity".

Explaining to 'Variety', he said that once the strike was officially called, they were "going to walk obviously in solidarity".

He went on to add: "That's why we moved this (red carpet) up because we know the second it's called, we're going home."

The decision to strike came after negotiations with the Alliance of Motion Picture and Television Producers (AMPTP) failed to produce new contracts for members on Thursday. It comes after weeks of bargaining with the AMPTP who represent some of the biggest studios and streaming platforms.

Union president Fran Drescher announced the strike which started at midnight Pacific Time in the US. The 'Oppenheimer' cast joins the likes of Jennifer Lawrence, Meryl Streep and Mark Ruffalo who have all decided to join the strike. It comes after Disney boss Bob Iger claimed those taking part are "not being realistic" and are being "disruptive" to the movie industry.