Bret Easton Ellis fumes after Fifty Shades film goes to a British writer

Novelist lobbied for the screenplay job and had proposed his own casting ideas

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. The American novelist Bret Easton Ellis has lashed out after producers rejected his bid to bring EL James's bestseller to the screen in favour of a little-known British writer.

EL James, author of the erotic literary phenomenon which has sold 40 million copies worldwide, 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 film.

Marcel, best-known for penning Terra Nova, a US television science-fiction series which was cancelled after one series, 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: the creator of (gulp) Terra Nova and a Mary Poppins biopic has been blessed by EL James and no one can stop her. Dear God." He added: "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, the team behind the Oscar-winning Social Network, defended their choice. "Kelly's work demonstrates her flawless structural technique and passionate commitment to emotion, humour and depth of character which is particularly visible in the celebrated screenplay for the upcoming Saving Mr Banks," said De Luca.

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.

Brunetti declined to be drawn on who will play James's key protagonist, billionaire businessman Christian Grey. Universal and Focus Features anticipate turning the Fifty Shades books into a film trilogy.