Acting knights Patrick Stewart and Ian McKellen are set for a return to the X-Men movie franchise, alongside the stars who played their super characters as young men.

Director Bryan Singer has revealed the two British thespians will join X-Men: First Class stars James MCAvoy and Michael Fassbender in his new blockbuster X-Men: Days of Future Past.

Tweeting the casting news to fans, Singer, who directed the original X-Men in 2000 and 2003's X2, writes, "Thrilled to announce @ianmckellen118 & @SirPatStew are joining the cast of #Xmen #DaysOfFuturePast."

Stewart and MCAvoy have both portrayed wheelchair-bound Professor X in the X-Men films, while MCKellen and Fassbender have played good-guy-gone-bad Magneto in the superhero movies.

The new film is expected to hit cinemas in 2014.