Aaron Sorkin's 'The Trial of the Chicago 7' has been put on hold.

Aaron Sorkin

Aaron Sorkin

The 57-year-old director was due to write and helm the movie, which has Sacha Baron Cohen, Eddie Redmayne and Jonathan Majors attached, but the filmmaker is said to be concentrating on his Broadway play 'To Kill a Mockingbird' for the time being.

Producers Amblin Entertainment - founded by Steven Spielberg - said in a statement: "Aaron just adapted 'To Kill a Mockingbird,' which is premiering on Broadway this Thursday.

"He is currently evaluating his schedule and commitments to determine the best time and way to make 'The Trial of the Chicago 7'. Amblin remains involved as a producer."

Sources told Variety that Sorkin in focusing on his play ahead of its Thursday (13.12.18) release.

The movie will be based on the 1969 trial of seven defendants who were charged by the federal government with conspiracy, following the counter-cultural protests in Chicago at the 1968 Democratic National Convention.

Sources told The Hollywood Reporter that the motion picture was in pre-production and heading for a February start, but insiders claim budgetary concerns could've played a part in putting the movie on hold.

But this is not the first time the film has faced issues.

Spielberg initially considered directing the political drama himself in 2008, but the film was delayed because of a writer's strike and he then couldn't find the time to take it on.

The filmmaker tried to get the motion picture off the ground again in 2013, with Paul Greengrass attached to direct, but he moved on and the project was shelved due to budget issues.

But Sorkin was later approached after he made his directorial debut in 2017's 'Molly's Game'.