Photo: © Getty Images

Sean Penn has launched a blistering attack on the Academy Awards for "limiting filmmaking".

The 64-year-old star has won two Best Actor Oscars for 'Mystic River' and 'Milk' respectively but had a scathing verdict on the "extraordinary cowardice" of those who vote for the Academy Awards for a lack of risk-taking when it comes to prize winners.

Speaking at the Marrakech Film Festival, where he received a lifetime achievement award, Sean said: "The Academy have exercised really extraordinary cowardice when it comes to being part of the bigger world of expression, and in fact, have largely been part of limiting the imagination and very limiting of different cultural expectations.

"So I don't get very excited about what we'll call the Academy Awards (except for) when a film like 'The Florida Project', or 'I'm Still Here' (are nominated), or, you know, 'Emilia Perez', of the things that are likely to happen this year."

Penn pointed out that the lack of recognition for Ali Abbasi's Donald Trump biopic 'The Apprentice' – which stars Sebastian Stan as the businessman before his rise to president of the United States – typifies Hollywood's fear of the controversial.

The 'Carlito's Way' actor said: "It's jaw-dropping how afraid this business of mavericks is of a great film like that, one with great, great acting.

"(It's amazing) that they too can be as afraid as a piddly little Republican congressman."

Penn explained that he would encourage budding actors and filmmakers to make stories that are as "politically incorrect" as possible.

He said: "Around the world (there is) the demand for diversity – but not diversity of behaviour and not diversity of opinion or language. I would just encourage everybody to be as politically incorrect as their heart desires and to engage diversity and to keep telling these stories."

Penn has recently produced the historical thriller 'September 5' and had high praise for the movie's director Tim Fehlbaum.

He said: "(Fehlbaum) did such a great job. The perspective was not one that I've seen, or that we've seen.

"We've seen those patches all the time with different slogans. My favourite one is 'Suck Less'. I like to work with people who suck less."

Penn starred as gay rights activist and politician Harvey Milk in the 2008 picture 'Milk' but said he would not be able to play the part if the film was made now as Hollywood is "too timid" to cast straight actors as queer characters.

He told the New York Times newspaper: "It could not happen in a time like this.

"It's a time of tremendous overreach. It's a timid and artless policy toward the human imagination."

Sean also revealed that he had been "miserable" on film sets ever since he appeared in 'Milk', to the extent that he questioned his future in the industry.

He explained: "I went 15 years miserable on sets. I was faking my way through that stuff and that was exhausting.

"Mostly what I thought was just, ‘What time is it? When are we going to get off?’… I was sure it was done, but I didn’t know how I was going to keep my house running or travel freely or things like that if I stopped."