Emma Thompson says she enjoyed taking on the role of P.L. Travers in Saving Mr Banks as she was able to 'let out my inner-prickly pear.
The actress takes on the role of the author in a film about the creation of the film Mary Poppins.
Travers was the author of the book and battled with Walt Disney over selling the rights to the novel and her most beloved character.
But Travers was a woman who said whatever she thought, and Thompson thoroughly enjoyed that aspect of the role.
Speaking at the Press Conference for the film the actress joked: "I just let out my inner-prickly pear. I just, basically, was my true self. I just let it all hang out!
"I've got to tell you, it was such a relief to be rude without any repercussions whatsoever. Can you imagine it? 'I don't want to go to your f***ing press conference' or 'I don't want to go to your birthday party because I got bored of you years ago.'
"You could just come out with these things, and she did! She said what she meant."
Saving Mr Banks sees Thompson team up with Tom Hanks - who plays Walt Disney - while John Lee Hancock is in the director's chair.
Thompson and Hanks walked the red carpet in Leicester Square last night as the movie officially closed the BFI London Film Festival.
Saving Mr Banks is released 29th November.
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