Emma Thompson is also in talks to join the film as children's author P.L. Travers, upon whose book Mary Poppins is based.
Kelly Marcel wrote the screenplay, which wound up on 2011's Black List. The story will mainly focus on P.L. Travers's life, and her apprehension at having her literary character brought to the big screen.
There is no production start date set at this time.
Saving Mr. Banks was released December 13th, 2013 and stars Emma Thompson, Tom Hanks, Annie Rose Buckley, Colin Farrell, Ruth Wilson, Paul Giamatti, Bradley Whitford, B.J. Novak. The film is directed by John Lee Hancock.