Rock legend Mick Jagger attacked US President Donald Trump for his rudeness and lies on Saturday and for "tearing apart" environment controls when America should be setting the standard for the world.
The Rolling Stones singer said he was "absolutely behind" young climate change activists who had earlier occupied the red carpet at the Venice film festival, where he was starring in the psychological thriller, "The Burnt Orange Heresy".
Jagger said he deplored how politics has descended into name-calling, "including in my own country this week" -- a reference to British Prime Minister Boris Johnson comparing opposition Labour leader Jeremy Corbyn to a "big girls blouse" and a "chlorinated chicken".
The icon, now 76, bewailed "the polarisation and incivility in public life", although the one-time bad boy of 1960s rock admitted he was "not always for civility" himself.
"But when you see it now... in so many countries, including my own this last week, but particularly the US, it's a sea change.
"It is not about manners," Jagger insisted, saying he was fearful about "where all this polarisation and rudeness and lying is going to lead us."
But more worrying still, said the singer, was that what little environmental safeguards there were being swept away across the globe.
"We are in a very difficult situation at the moment, especially in the US, where all the environmental controls that were put in place -- that were just about adequate -- have been rolled back by the current administration so much that they are being wiped out," he added.
Jagger, who rarely comments on politics, said "the US should be the world leader in environmental control but now it has decided to go the other way.
"I am so glad that people feel so strongly about that that they want to protest," said, referring to young activists from Greta Thunberg's Friday for Future movement who sprayed "Listen to your children" and "Make the red carpet green" on the festival's red carpet.
His co-star Donald Sutherland echoed his call to protest and urged people to take to the streets and vote out Trump, Johnson and Brazil's far-right leader Jair Balsonaro.
"Mick is right, the controls (in the US) under Obama were barely adequate -- now they are being torn apart. It's the same in Brazil and they will be torn apart in England" after Brexit," he warned.
"When you are 85 years old and you have children and grandchildren, we will leave them nothing if we do not vote those people out of office in Brazil and in London and in Washington.
"They are ensuring the ruination of the world", something that "we have all contributed to", Sutherland added.
The Venice film festival ends on Saturday night. The winning movie for the last two years has gone on to win the best picture at the Oscars.