Vaughn denied that the reason he left X-Men: The Last Stand was the prospect of taking on such a large-budget film:
"Big movie-making is a lot easier than small movie-making," he says. "All these big directors and producers would be struggling if you gave them a million dollars and told them to make a movie for that amount.
"What happened with X-Men: The Last Stand was I didn't have the time to make the movie that I wanted to make. I had a vision for how it should be, and I wanted to make sure I was making a film as good as X2: X-Men United and I knew there was no way it could be. I just suddenly knew it wasn't the right thing for me to do.
"It was a tough decision because it was a hell of an opportunity. But I was trying to make a career as a director, and I didn't want to be the guy accused of making a bad X-Men movie."
Brett Ratner ended up directing the film, and Vaughn was not impressed. "As it happens, I could have made something a hundred times better than the film that was eventually made," he says. "It sounds arrogant, but I could have done something with far more emotion and heart. I'm probably going to be told off for saying that, but I genuinely believe it."
Vaughn is getting another chance at directing a movie based on a Marvel Comics character - he is currently at work on an adaptation of Thor.