Sean Penn has become the second Oscar-winning actor to accuse America's rightwing Tea Party movement of institutional racism.

Speaking on CNN's Piers Morgan Tonight on Friday, the same show upon which Morgan Freeman said the organisation was fuelled by a desire to "do whatever we do to get this black man ... outta here" last month, Penn went even further in his vilification of the political group.

"I don't think there's any doubt about it," he said. "If you ask any representative of the Tea Party, 'OK, social security, socialist, get rid of it?' they're going to get very confused. At the end of the day, there's a big bubble coming out of their heads, saying, 'Can we just lynch him?'"

Penn had earlier described the Tea Party as a "distraction" in the forthcoming US presidential elections. "You have what I call the 'Get the N-word out of the White House party', the Tea Party," he said. "This kind of sensibility, which is much more of a distraction."

Other Hollywood figures who have accused the Tea Party of acting out of racist motivations include comedians Bill Maher and Janeane Garofalo. Speaking in response to Freeman's comments last month, the movement's black presidential hopeful, Herman Cain, said he did not believe the actor had been to a Tea Party event. "Most of the people that are criticising the Tea Parties ... about having a racist element, they have never been to a Tea Party," he added.