Hollywood actors will join writers on the picket line, sparking an industry-wide shutdown in a row about pay and the impact of artificial intelligence.

The strike, which starts at 8am UK time on Friday, comes after the union which represents around 160,000 members of the industry and Hollywood studios failed to reach an agreement on a fairer split of profits and increased safeguarding around AI rights.

Shortly before the action was announced on Thursday evening, the stars of upcoming historical epic Oppenheimer staged a walkout from the film’s London premiere in solidarity with other union members.

Cillian Murphy, Emily Blunt and Matt Damon were among the actors who left the event to “write their picket signs”, director Christopher Nolan told audiences.

Members of the Screen Actors Guild – American Federation of Television and Radio Artists (Sag-Aftra) – previously voted overwhelmingly to authorise a strike if a new contract with major studios, streamers and production companies could not be reached.

Nearly 98% (97.91%) of the 65,000 members who cast votes were in favour, Sag-Aftra said.

It comes amid the ongoing strike by more than 11,000 members of the Writers Guild of America (WGA), who began industrial action on May 2.

It is the first time in more than 60 years that both unions have been on strike simultaneously.

Speaking on stage at the Oppenheimer premiere ahead of the official strike announcement, filmmaker Nolan said: “I have to acknowledge the work of our incredible cast, led by Cillian Murphy.

“The list is enormous — Robert Downey Jr, Matt Damon, Emily Blunt, Florence Pugh, Kenneth Branagh, Rami Malek and so many more. You’ve seen them here earlier on the red carpet.

“Unfortunately, they are 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 their union.”

Speaking on the red carpet earlier, Sir Kenneth Branagh told the PA news agency: “If it happens I stand in solidarity with our Sag members.”

Murphy told PA: “I stand by my colleagues, that’s all I can say to you.”

Meanwhile, British actress Pugh said that the cast felt lucky to have got to the Oppenheimer premiere before the strike was announced but also lucky to be standing in solidarity with their acting peers.

The Sag-Aftra strike will pile yet more pressure on the industry which has seen multiple projects and award ceremonies delayed or cancelled since the start of the writers’ strike in May.

Upcoming award shows, premieres, events and film festivals around the world, including the Toronto and Venice film festivals, and the 75th Emmys are likely to go ahead without participation from major talent, if at all.

Among the productions in the UK that could be affected by the strike action is Deadpool 3, starring Hollywood actors Ryan Reynolds and Hugh Jackman, who were both recently pictured suited up for filming.

The third instalment of the popular antihero franchise is scheduled for release in May 2024 but the strike action could significantly affect production.

We know it is a critical time at this point in the industry and the issues need to be addressed, difficult conversations, I know everybody is trying to get a fair deal, that is what’s required so we’ll support that.

A number of TV series being filmed in the UK might also be affected, including spy thriller The Day Of The Jackal starring Oscar winner Eddie Redmayne and period boxing drama A Thousand Blows with Stephen Graham.

House Of The Dragon series two with Matt Smith and Emma D’Arcy could also be affected, alongside the second series of The Sandman with Tom Sturridge and the fourth series of Slow Horses with Academy Award winner Gary Oldman.

Announcing the strike at a Los Angeles press conference on Thursday, the union’s president Fran Drescher said: “The gravity of this move is not lost on me… it’s a very serious thing that impacts thousands if not millions of people.

“This is a moment of history that is a moment of truth. If we don’t stand tall now we are all going to be in trouble.”

Asked how long the strike would last, Ms Drescher said: “That’s up to them, we are open to talking to them tonight.

“All of this is because of their behaviour, it’s up to them if they want to talk in a normal way.”

Meanwhile, British actors’ union Equity said it stands “full square behind our sister union”, stating it has also been experiencing “bullish engagers attempting to undermine its collectively bargained agreements”.

A statement from the Alliance of Motion Picture and Television Producers said it was “deeply disappointed” that the union had decided to “walk away from negotiations”.

“This is the union’s choice, not ours,” the statement read.

“Rather than continuing to negotiate, Sag-Aftra has put us on a course that will deepen the financial hardship for thousands who depend on the industry for their livelihoods.”