The Milk star, 62, is at the French Riviera event to promote his new movie, Black Flies, which shocked the audience with its abundant blood and gore this week.
“The industry has been upending the writers, actors and directors for a very, very long time,” Penn told the press.
The US actor denounced the idea that Artificial Intelligence could soon be used to write Hollywood screenplays – as has been suggested by some groups.
“My full support is with the writers guild,” he said. “There are a lot of new concepts that are being tossed about, including the use of AI. And it just strikes me as human obscenity that there’s been a pushback [from the studios] on that.”
“The first thing we should do in these conversations is change the Producers Guild and title them how they behave, which is the Bankers Guild,” added Penn. “It’s difficult for so many writers and so many people industry-wide to not be able to work at this time. I guess it’s going to soul-search itself and see what side toughs it out.”
He later clarified in a statement to Variety: “I misspoke. I meant to say AMPTP [Alliance of Motion Picture and Television Producers], not PGA.”
Black Flies stars Tye Sheridan as a young paramedic in a Training Day-esque plot that sees him get a rough-and-ready lesson in lifesaving techniques from a grizzled veteran (Penn) in New York City.
Penn’s comments come as the potential for a wider work stoppage in Hollywood may be growing. The Directors Guild is also negotiating a new contract with producers. The board of SAG-AFTRA, the actors union, this week voted to ask members for strike authorisation as it prepares to enter negotiations for a new contract.
In Cannes, the strike has been a regular topic for American stars. On Thursday, Ethan Hawke wore a shirt that read “Pencils Down.” On the festival’s opening day Tuesday, juror Paul Dano said he planned to join his wife, Zoe Kazan, on the picket lines soon.
“My wife is currently picketing with my six-month-old strapped to her chest,” said Dano. “I will be there on the picket line when I get back home.”
Additional reporting by The Associated Press