Easton Ellis fury as Brit writer gets '50 Shades' film

Kelly Marcel, the British writer chosen to adapt the bestseller for the big screen (David Sandison)

If the film of Fifty Shades Of Grey proves as heated as the battle over who gets to write the adaptation then a box office bonanza is assured.

American novelist Bret Easton Ellis has lashed out after producers rejected his bid to bring EL James' best-seller to the screen in favour of a British unknown.

EL James, author of the erotic novel, said she was "thrilled" after Universal Pictures announced that Kelly Marcel, a former actress in The Bill and Casualty, would be the screenwriter on the hotly-anticipated film. Marcel, best-known for penning Terra Nova, a US television sci-fi series which was cancelled after one season, emerged triumphant after a three-month selection process. Ms James tweeted that she was "thrilled to announce" Marcel's role.

However Easton Ellis, the American Psycho author who lobbied for the job and proposed his own casting ideas, was furious. He mocked Marcel's biography, which includes Saving Mr Banks, a forthcoming film starring Tom Hanks and Emma Thompson about Disney's pursuit of the rights to film Mary Poppins.

Easton Ellis tweeted: "Kelly Marcel?!? KELLY MARCEL?!? Kelly Marcel is WRITING the script for Fifty Shades of Grey?!? THIS is the movie they want to make? ARGH."

The Fifty Shades producers, Michael De Luca and Dana Brunetti, defended their choice. Brunetti hit back at Easton Ellis, mocking a trailer for the writer's new film, The Canyons, starring Lindsay Lohan and porn actor James Deen. "Really, Bret? The day you release that 'trailer'. School film? You're losing it...," Brunetti tweeted. Marcel declined to join the Twitter spat but tweeted: "Beyond thrilled to be jumping aboard the 50 Shades train. Very exciting."

There is no word on who will play the book's protagonists. Marcel is close friends with the British star, Tom Hardy, while Ryan Gosling and Mila Kunis are currently tipped for the lead roles.