Matthew Vaughn's "heart sank" when he first saw 'Inception' as it had similarities to his forthcoming prequel 'X-Men: First Class'.

The director has had to make a number of changes to his script for the forthcoming superhero prequel as he was worried people would accuse him of copying Christopher Nolan's movie about a group of dream thieves.

He said: "I saw 'Inception,' which I loved. But my heart sank when I saw that a few of the ideas we had were up on the screen. So it's either leave it in and look as if you're copying or change things.

"We completely ripped out about 12 pages of The Script and the storyboards."

The new movie will follow the early friendship of Charles Xavier and Erik Lensherr as they struggle with their mutant abilities and set up a school for gifted youngsters.

While he hopes to avoid comparisons to 'Inception', Matthew welcomes feedback similar to the reception given to Jj Abrams reimagining of 'Star Trek' last year.

He told ComingSoon.net: "Obviously Abrams couldn't make everyone happy with that one, but he did a pretty good job. He made a fantastically exciting reinvention of that world, with those great characters. And I think there will be comparisons a little bit with 'X-Men: First Class.' It's very similar, in a way. But we're doing some cool stuff in this movie, some really cool stuff that you haven't seen before."

'X-Men: First Class' will star James McAvoy, Michael Fassbender, Nicholas Hoult and Kevin Bacon.