Michael Sheen is to give up acting to fight the rise of the far-right, and will leave Hollywood to return to his native Port Talbot in Wales to do so.
"In the same way as the Nazis had to be stopped in Germany in the Thirties, this thing that is on the rise has to be stopped," he told The Times.
Sheen, best known for playing Tony Blair, Brian Clough and David Frost, said: "It will be a big change for how people relate to me. 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."
Last year Sheen gave a speech in Wales defending the NHS which was widely shared on social media, telling the crowd: "There is never an excuse to not speak up for what you think is right."
Sheen said the election of Donald Trump had compelled him to take action. "It's not going to look like this in ten years' time. Ever ything has shifted. The dice are being rolled again,” he said.
