Damon: 'Bourne 4 script still unfinished'

Matt Damon has revealed that the fourth instalment of the Bourne franchise is still years away from completion.

The actor announced in March that he and director Paul Greengrass are developing an original script for the next movie in the series, which is based on the books by Robert Ludlum.

Damon has now told Total Film: "Personally, selfishly, we'd all really like to do it, but we are really serious about trying to get the story and the script right because the only thing more disappointing than not having another one of these movies is - for us and for movie fans - to make one that isn't good.

"Everyone would say, 'They should have quit after three'. And we'd feel that way, too. We don't have the script yet, but hopefully we'll all be shooting in 18 months or so."

In July, it was reported that the screenplay would be ready in around one month.