Dennis Quaid will star as President Clinton, Michael Sheen will portray British Prime Minister Tony Blair and Julianne Moore will play Hillary Clinton in “The Special Relationship,” an HBO film about the unique and sometimes turbulent political relationship between the newly installed PM and the U.S. president.

The film isn’t greenlit yet but is expected to mark the directing debut of “Frost/Nixon” playwright Peter Morgan, who wrote the screenplay.

Sheen, who starred as David Frost in “Frost/Nixon,” played Blair in the Morgan-scripted “The Deal” and “The Queen.” Helen McCrory, who played Cherie Blair in “The Queen,” will reprise that role in “The Special Relationship.”

Kathleen Kennedy and Morgan are exec producers, along with Andy Harries. Frank Doelger and Ann Wingate are producers. HBO is in discussions with the BBC to come aboard as a producing partner.

Quaid, who next stars in “G.I. Joe: The Rise of Cobra,” will be honored by ShoWest as Male Star of the Year.

The casting broke on several websites Tuesday.