Kate Winslet under fire over pro-marijuana film

Kate Winslet in the movie Carnage. Photo/supplied

Kate Winslet has been labelled "silly and irresponsible" for apparently endorsing a campaign to legalise cannabis.

The Oscar-winning actress appeared in a YouTube clip on the internet alongside Sir Richard Branson to promote Breaking the Taboo, a documentary made by his son Sam, which supports decriminalising drugs.

The film is part of a campaign to "end the war on drugs".

Winslet, 37, is dating Branson's nephew Ned Abel Smith - now known as Ned Rocknroll after changing his name by deed poll.

She does not appear in the documentary but says in the clip: "I'm Kate Winslet and I'm breaking the taboo."

It is understood Winslet got involved because of her relationship with Ned, 34.

A source close to Winslet, who won an Oscar for her role in The Reader in 2008, said she was happy to encourage debate but was not calling for drug legalisation.

However, anti-cannabis campaigner Mary Brett described Miss Winslet's actions as "completely irresponsible".

Mrs Brett added: "She's a role model for all sorts of young people. A lot of these celebrities jump on the bandwagon to be trendy and cool. It's this message from celebrities going to kids that drugs are OK and they're not. I would hope she realises how silly she is."

Miss Winslet's name has been removed from a list of supporters on the campaign's website.

A source said it had been included by mistake.

The source added: 'Kate does not, and never has, used drugs.'

- Daily Mail