Peter Morgan has started work on a follow-up to The Queen that will dig into former U.K. prime minister Tony Blair's relationships with U.S. presidents Bill Clinton and George W. Bush, according to Variety.

The movie will focus on Blair's reaction to the handover of power from Clinton, a natural liberal ally, to Bush, who came from the other end of the political spectrum.

The project will be the third film in Morgan's "Blair trilogy," which began with Channel 4 telepic The Deal and continued with The Queen. Michael Sheen is expected to reprise his role as Blair.

According to the trade paper, Morgan initially considered tackling the more obvious drama surrounding the run-up to the Iraq war, when Blair fatally compromised his own premiership through his wholehearted support for Bush's invasion plans. But in the end Morgan decided that the roots of those events lay in Blair's difficult adjustment to the transition from Clinton to Bush a few years earlier.

Morgan is researching the project with a plan to start writing by the end of this year.