Scarlett Johansson And Gwyneth Paltrow have fallen out on the set of their new film Iron Man 2, it's been reported.

Gwyneth, who plays the character Pepper Potts, is said to be frustrated that her co-star is constantly demanding of the crew's attention.

The sour relations between the pair, who are said to have struggled to get on in the past, have created an unhappy atmosphere on set, according to The Sun newspaper.

“They come from different worlds and have completely different styles,” a source said.

Gwyneth has apparently taken advantage of a two week break in filming by joining her husband, Chris Martin, on Coldplay's US tour.

The sequel to X Men will see Scarlett play Natasha Romanoff, who is also known as the spy Black Widow.

The character's tight-fitting catsuits and hands on combat scenes are also believed to have upset Gwyneth, who's character is more business-like.

The film, which also features Robert Downey Jr and Oscar-winning actor Mickey Rourke, is out next year.

Scarlett Johansson