Days before his new film “Passengers” is sure to make a killing at the box office, actor Michael Sheen has announced he will become a political activist ― and may begin acting less.

Sheen, who is well-known for his breakthrough performance as Tony Blair in a trio of films about the former British prime minister, revealed his decision in an interview with The Times of London on Saturday.

The “Frost/Nixon” actor has been active in politics throughout his career, but apparently the rise of far-right populism in both the United States and the United Kingdom inspired him to fully commit to fight against “demagogues” and “fascists.” He cited Donald Trump’s presidential victory and the results of the Brexit vote as some of the reasons for leaving Hollywood.

“In the same way as the Nazis had to be stopped in Germany in the ‘30s, this thing that is on the rise has to be stopped,” he told The Times. “It’s not going to look like this in 10 years’ time. Everything has shifted. The dice are being rolled again.”

The Times characterized Sheen’s comments as a decision that the entertainer was quitting acting, but Sheen tweeted Saturday that he hasn’t given up the profession. He also said he’s not focusing specifically on the Brexit vote, but rather the “general world rise of anti-democratic forces.”

Before this gets ridiculous I said I'm thinking I might start acting less and maybe even stop for a while at some point but don't know yet. — michael sheen (@michaelsheen) December 17, 2016

Brexit will of majority&totally understandable. Not about that. Talked about general world rise of anti-democratic forces. Must be stopped. — michael sheen (@michaelsheen) December 17, 2016

After living in Los Angeles for the past 14 years, Sheen plans to spend the foreseeable future in his hometown of Port Talbot in South Wales, which he says voted in favor of leaving the European Union, to organize on a grassroots level.

“It will be a big change for how people relate to me,” he explained to The Times. “Once I’m in, I’m fully in, and this is big. As soon as you start to be effective, then people try to crush you, because it’s dangerous.”

After news of his political plans broke, Sheen shared a Ronald Reagan quote on Twitter to emphasize what exactly is at stake in our current political moment.

“Freedom is never more than one generation from extinction....It must be fought for, protected, and handed on....” he wrote.

"Freedom is never more than one generation from extinction....It must be fought for, protected, and handed on...." - Ronald Reagan — michael sheen (@michaelsheen) December 17, 2016

Sheen’s girlfriend, comedian Sarah Silverman, expressed her support by retweeting a particularly powerful speech he delivered in support of Britain’s National Health Service in 2015.

This post has been updated with Sheen’s Saturday tweets that clarify he doesn’t plan to quite acting altogether immediately.