SAVING MR. BANKS

Saving Mr Banks is about the real-life battle of wills between Travers and Disney over the movie rights to Mary Poppins.

Thompson admits the prickly novelist has been one of her most difficult roles and describes the author as "deeply contradictory".

Disney had been after the rights to the book for 20 years and the film focuses on a trip Travers makes from London to Hollywood in 1961 to finally discuss the project with Disney face-to-face.

The film also flashes back to Travers' childhood in 1906 Australia and shows how her relationship with her father, played by Colin Farrell, shaped both her career and the character of Mr Banks in Mary Poppins.

With an original screenplay by British writer-producer Kelly Marcel, whose next film project is Fifty Shades of Grey, Saving Mr Banks is the first full-length cinema drama to depict Walt Disney himself.

"I felt that it was going to be difficult to cast - you need to have an icon playing an icon," says Hancock, who directed 2009's The Blind Side, for which Sandra Bullock won a best actress Oscar. "If Tom had said no I'm not sure what we would have done."

Hancock points out that the film is not a Walt Disney biopic. "It's not about him, it's about PL Travers - it's just two weeks in his life in 1961."

Before signing away the book's rights, Travers demanded control over the script and the work of sibling composers Richard and Robert Sherman, whose original songs in the film included A Spoonful of Sugar and Let's Go Fly a Kite.