Bale forced 'major Terminator rewrite'

The makers of Terminator: Salvation have said that star Christian Bale forced a major rewrite on the upcoming movie.

The actor was initially approached by director McG to play the part of main character Marcus Wright, according to Reuters.

However, he insisted that he wanted to play John Connor, a role that was initially just a small part of the fourth film in the franchise.

The director said that he worked tirelessly with the Dark Knight star to incorporate the character as a more prominent presence and that the script became a challenge as a result.

"A lot of the work was integrating [Connor] into scenes... and having that feel integral and sensible, as opposed to grafted on just because there was a star in the part," screenwriter John Brancato said.

The latest instalment will now feature equal screen time for the characters of John Connor and Marcus Wright (Sam Worthington), a fellow freedom fighter waging war against the machines.

Terminator Salvation opens in the US on May 21 and the UK on June 3.