Robert Downey Jr's Due Date Fights

Robert Downey Jr's Due Date Fights

Robert Downey Jr. argued with director Todd Phillips about how to shoot every scene on 'Due Date'.

The 'Iron Man' actor's co-star Zach Galifianakis reveals the pair would regularly gather in his trailer on the set of the comedy movie to fight out how a scene would be shot for "an hour and a half" before they went to work.

He said: "Robert has his opinions. And I love to watch him give his opinions because he's incredibly eloquent and he makes me laugh.

"So I would sit back while these two smart men went at it for maybe an hour and a half about how we were going to shoot a scene."

However, Galifianakis - best known for his role in surprise 2009 hit 'The Hangover'- confesses he never got involved in the discussions and instead hosted the debates.

He told the Scotsman newspaper: "Well, I didn't really want to be around, but maybe that was why they used my trailer. If it had been Robert or Todd's, I probably wouldn't have come."

'Due Date' - which tells the tale of a father-to-be (Downey Jr.) who is forced to hitch a ride with an aspiring actor (Galifianakis) in order to see the birth of his child - is released worldwide throughout Early November.