Long rumored, director Bryan Singer has now confirmed that the upcoming X-Men: Days of Future Past will mix cast members from his X-Men and X2 with those from Matthew Vaughn's X-Men: First Class. Taking to Twitter, Singer reports that Ian McKellen and Patrick Stewart are set to reprise their roles as Magneto and Professor X with Michael Fassbender and James McAvoy returning to play younger versions of the same characters.

Singer goes on say that Nicolas Hoult will be back as Beast and Jennifer Lawrence as Mystique. His original tweets read as follows:

I'd like to officially welcome back James McAvoy, Jennifer Lawrence, Michael Fassbender, & Nicholas Hoult to #XMEN for #DaysOfFuturePast

— Bryan Singer (@BryanSinger) November 27, 2012

Thrilled to announce @ianmckellen118 & @sirpatstew are joining the cast of #XMEN #DaysOfFuturePast #magneto #professorX More to come...

— Bryan Singer (@BryanSinger) November 27, 2012

Scheduled for release on July 18, 2014, X-Men: Days of Future Past boasts a script by Simon Kinberg and is said to be inspired Chris Claremont and John Byrne's comic book storyline that ran in Uncanny X-Men #141 and 142 back in 1981. "Days of Future Past" introduced the idea of an alternate future for Marvel's mutants that grew out of the Brotherhood of Evil Mutants killing an important senator, leading to a future where all mutants are hunted by Sentinels.

Although not yet officially listed, Singer's "more to come" is likely to also include Hugh Jackman as Wolverine. In addition to playing a key role in the comic book version of the story, Wolverine has appeared in every live-action X-Men film to date and will star in his second solo adventure with the July 26 release The Wolverine.