Michael Fassbender has pulled out of starring in new Western movie 'Jane Got A Gun'.

The 35-year-old actor has decided to turn down a part in the project, which stars Natalie Portman in the lead role, to be replaced by Joel Edgerton.

The movie's plot centres around titular character Jane (Portman) whose outlaw husband returns home after being shot by his double-crossing gang. When the treacherous mob arrive in town to kill her spouse, Jane asks a former lover to help her defend him and her home.

Fassbender was going to play the ex-lover but due to a shooting conflict with 'X-Men: Days of Future Past' - which is filming in Montreal, Canada - he has had to pass on the project.

Edgerton had already signed up to play the gang leader but has now switched roles and will portray the heroic ex.

Jude Law has been cast as the murderous gang leader in the movie - which will be directed by Lynne Ramsey.

Shooting is scheduled to start in New Mexico in April.