The British actress could not longer fit the part in to her busy schedule.
The film will tell the story of Eric Lomax, a World War II Japanese prisoner of war who was forced to work on the intimidatingly named “death railway”. Kidman will play Lomax’s wife Patti in the film which will see the husband and wife facing up to the damage done during those difficult years.
Colin Firth is set to play older Lomax while War Horse’s Jeremy Irvine, will play his youthful incarnation.
Some filming is rumoured to be taking place on Australia’s Gold Coast (which will stand in for 1940s Burma) but Scotland is first on the shooting schedule in April.
Meanwhile, Weisz will next be seen in Oz: The Great And Powerful, directed by Sam Raimi, and Bourne Legacy alongside Jeremy Renner.