Robert Downey Jr and Zach Galifianakis in “Due Date”

Robert Downey Jr has been confirmed to star in Due Date.

The Iron Mans actor will join Zack Galifianakis (The Hangover) in the Todd Phillips comedy.

Downey Jr will reportedly play a father-to-be who is racing to get home for the birth of his child.

The film begins this September in Atlanta, Arizona and Los Angeles.