Matthew Vaughn, the director of Kick-Ass and X-Men: First Class, has revealed that he will not direct X-Men: Days of Future Past, as was previously expected, according to Deadline. The report suggests that Fox is pursuing X-Men and X2: X-Men United director Bryan Singer to take over the film, with Vaughn moving on to a film adaptation of Mark Millar and Dave Gibbons's Secret Service. Millar, of course, recently took over an advisory role for 20th Century Fox's Marvel Comics movies, which would give him input into such a decision. Singer, meanwhile, hasn't directed an X-Men film in years but has had a producer's credit on all of them and was reportedly involved in an advisory capacity on X-Men: First Class. He originally left the franchise to direct Superman Returns, and was replaced for the third X-Men film by Brett Ratner. Both X-Men: The Last Stand and Superman Returns were massive critical disappointments, although Ratner stands by his film's commercial successes in interviews, while Singer has been more open about some of the mistakes he made on Superman. While Singer's films would seem to have been "rebooted" out of existence by X-Men: First Class, Days of Future Past was, in the comics, a time-travel story that involved a lot of continuity acrobatics. Most commentators have expected that the time-traveling nature of the movie would help to bridge the gap and repair "disagreements" between the two franchises. It's been widely rumored that Patrick Stewart, Famke Janssen and Hugh Jackman could return to reprise their roles from the Singer/Ratner films. Janssen is also rumored to be appearing in The Wolverine, which this morning was revealed to be a sequel, rather than a prequel as previously expected, to Singer's X-Men. Vaughn has already turned in a first draft of the film, which Deadline speculates will have to replace him as director quickly in order to make its July 18, 2014, target date. He almost left X-Men: First Class around this same point in production, but returned to it, and then elected to hand off the Kick-Ass franchise, also based on comics by Mark Millar (with artist John Romita, Jr.), to Jeff Wadlow in order to work on the X-Men: First Class sequel instead. What, if any, impact a delay would have on the film's shooting schedule is not immediately clear; while Jennifer Lawrence is under contract to come back, her starring role in The Hunger Games films has been planned around X-Men: Days of Future Past's shooting schedule. Don't hold your breath yet, though; Singer was at one point rumored to be directing X-Men: First Class, as well.