Having directed the first two instalments in the X-Men franchise, were you not tempted to helm X-Men: First Class yourself?
I was already committed to doing Jack the Giant Killer and I also saw this as an opportunity to produce something. My company [Bad Hat Harry] has done a number of things but nothing this big. It was such a great opportunity to make this the first big studio picture from Bad Hat Harry and from me as a producer. I thought if I could find the right filmmaker who understood what I wanted out of it and who had reverence for the first two X-Men pictures, which Matthew had—he was very much keyed off those movies and we got along—I realised it could be a really fun experience to see ideas I had come to life without me having to sit there every day on the set going ‘aaargh’, which can often be the experience on an aggressive schedule, like the one Matthew had making an X-Men film.

Were you in any way a co-director of the film?
No, not at all. It’s his movie. I wrote the story and I worked with writers to develop it, I brought Matthew in, I worked with him through the casting process and design ideas, but then I was very pleased with the rewrites he and Jane [Goldman] were doing. As a director I am not going to hover over another director; that’s not the way I would want to be produced. I help in any way I can, then in post-production I give my notes, and he honoured as many as he could or wanted to.

It’s fair to say that the two previous movies, X-Men: The Last Stand and the spin-off Wolverine were not all that well-received for critics. How do you respond to that?
It’s hard for me because I’m very sensitive to the fact those movies were made under certain circumstances that didn’t afford the directors all the protection and control that maybe Matthew had on this movie, and I had on the first two. There was a certain tone that may not have translated and it may have been because of those limitations. When Brett [Ratner] came onto The Last Stand he was already attached to a script and pre-visualisation that had already been done. The movie was half-made. When I make a movie I start from scratch; if I want to use something someone else developed that’s fine but I don’t have to. But Brett had so little time and he was under such parameters. With Wolverine I believe there was a certain tone but then it got kind of changed a bit, but if I’m not involved it’s hard for me to speak about it, and if I am involved it’s hard for me to be objective.

First Class boasts a phenomenal young cast; were they all of your first choices?
Pretty much, yeah. There were a few people we looked at before we knew other people were available, then suddenly people we really liked were available and we got them. I had to fight for Michael [Fassbender] because he wasn’t as established as James [McAvoy] but I just said ‘This guy is it’. That was the one time where Matthew said ‘I need your help to get this done’, because we both saw his audition tape and agreed that he was the guy.

And is it true you didn’t want James and Michael to study Patrick Stewart and Ian McKellen’s performances in the previous films?
Yes, that’s true. This was a time when they were different people, they were different characters. This was a time when Erik/Magneto was a very angry, vengeful victim of the Holocaust but also had enormous charisma and sex appeal. And it was a time when Professor X was much more naïve and idealistic and young, a time when they were romantic, a time when they hadn’t yet hardened into the characters. So the last thing we wanted them to do was sound like Ian McKellen and Patrick Stewart.

Unusually for a blockbuster, First Class deals with a powerful real-life event, the Cuban Missile Crisis. Why did you think this would make a good backdrop?
I thought the movie 13 Days was cool, and the fact we were on the brink of nuclear war and guys like General Curtis LeMay would have nuked Cuba in a second, the fact Castro said he would have advocated an exchange of fire even at the cost of his entire island, the very emotional telefax Khrushchev sent over that night… It was quite a gripping time. Because there were no cameras around, there was no Internet and no embedded journalists, we don’t really know exactly what happened in the ocean at that time and I thought, ‘What a great staging area for some big mutant thing that happened but we may not have known about’.

Did you have any worries about playing with the comic-book mythology?
No. Just as a writer who gets tasked to write a new X-Men comic wants to bring their own ideas to it, as a moviemaker it’s the same thing. You’re making a movie based on these characters and you want to make sure you capture the essence of them, but you can’t be a slave to the timelines. You try to use logic, like I was able to bring Mystique and Beast into this movie because they look so different they could be old souls in the other movies.

Given the current craze for 3D, was there any discussion about filming First Class in three dimensions?
When I first conceived the movie it was before the 3D craze. Suddenly now everything is in 3D but it never felt like this needed to be in that format. Jack the Giant Killer, which I’m directing now, does lend itself to the 3D format more. It’s a fantasy film and the pace is a little bit slower, whereas when you get into all that frenetic movement it changes the way you shoot. There would have been no physical way to pull it off and I never felt it was necessary and nor did Matthew [Vaughan]. We were never like ‘Damn, I wish we could be doing this in 3D’.