Acclaimed British screenwriter Peter Morgan has stepped down from the director's chair for The Special Relationship, his third film following key moments in the career of former British prime minister Tony Blair.

The Special Relationship — based on Blair's close bond with former U.S. president Bill Clinton from 1997 to 2000 — was to have been Morgan's directorial debut.

No reason was given for Morgan's departure. He remains listed as writer and an executive producer on the project.

British director Richard Loncraine, whose wide-ranging credits include the 1995 movie Richard III, the 2004 romantic comedy Wimbledon, and TV productions The Gathering Storm, My House in Umbria and Band of Brothers, will now helm the film.

Shooting is scheduled to begin in London on July 20, with British actor Michael Sheen set to reprise his role as Blair and Dennis Quaid slated to play Clinton. Actresses Julianne Moore and Helen McCrory will portray Hillary Clinton and Cherie Blair, respectively.

A co-production between BBC Films and HBO, The Special Relationship follows 2006's The Queen, about how Blair and the Royal Family dealt with the death of Diana, Princess of Wales, and the 2003 TV movie The Deal, about Blair and one-time rival Gordon Brown.

Award-winning screenwriter Morgan has won much acclaim for penning The Queen, The Last King of Scotland and both stage and film versions of Frost/Nixon. He recently agreed to write the screenplay for the next instalment of the James Bond action franchise.