Ed Harris has signed on to play Arizona Senator John McCain in the HBO movie Game Change.

Earlier this month we reported actress Julianne Moore signed on to play Sarah Palin, the Alaska governor who was plucked from obscurity to serve as John McCain's Vice Presidential candidate. The movie will follow the McCain/Palin saga all the way up to their defeat by President Barack Obama and Vice President Joe Biden.

Jay Roach will direct Game Change from a script by Danny Strong, which is adapted from the book by John Heilemann and Mark Halperin. Jay Roach and Danny Strong both previously collaborated on another HBO political drama, Recount.

Tom Hanks and Gary Goetzman will executive produce through their Playtone production company. It isn't known when production will start on Game Change yet.