Earlier this month, Nicholas Hoult, who will next be seen as young Hank McCoy / Beast in the Matthew Vaughn directed, X-Men: First Class scored the lead role in Bryan Singer‘s forthcoming fantasy film, Jack the Giant Killer. The story will focus on young Jack, who inadvertently breaks a longstanding peace between the humans and giants when he pursues a princess who was kidnapped by a giant.

Now, THR reports that Ewan McGregor (Haywire, The Impossible) is in negotiations to join the cast as the leader of the king’s royal guard who helps in fighting off the giants. McGregor would join Hoult, Stanley Tucci (Captain America: The First Avenger) who was recently cast as the movie’s villain, Roderick, the adviser to the king with shady plans to overtake the land of Cloister, and the combo of Bill Nighy (Harry Potter and the Deathly Hallows: Part 2) and John Kassir (The Gunrunner Billy Kane) who will each portray one of two heads of Fallon, the two-headed leader of the giants.

Jack the Giant Killer is slated to hit theaters in 2011.