The national board of the Screen Actors Guild-American Federation of Television and Radio Artists, or SAG-AFTRA, voted Thursday to go on strike, summoning its 160,000 members to hit the picket lines, union officials said.

But even before the announcement, the stars of Oppenheimer made their voices heard.

Matt DamonCillian Murphy and Emily Blunt walked out of the red carpet premiere of the film, which was taking place at London’s Leicester Square around 5 p.m. BST, Variety reports, with Damon explaining to the trade they planned the move.

“We talked about it,” Damon said. “Look, if it’s called now, everyone’s going to walk obviously in solidarity …That’s why we moved this [red carpet] up because we know the second it’s called, we’re going home.”

The current SAG-AFTRA contract expired at 11:59 p.m. PT Wednesday. The contract was originally going to expire on June 30, but was extended after SAG-AFTRA and the Alliance of Motion Picture and Television Producers, or AMPTP, reached an agreement.

The vote to strike comes on the heels of an ongoing Writers Guild of America strike, which began on May 2.

This is a developing story. Please check back for updates.

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