Faye Dunaway, Paul McGann and Brian Cox will star in The Biographer, a privately-financed British feature film which is due to crank up on March 31.
The film traces the events that led former royal journalist Andrew Morton to write his biography of the Princess of Wales, Diana: Her True Story.
McGann will play Morton, Cox his publisher and Dunaway a hostile royal journalist.
The Biographer will be directed by Philip Saville, whose credits include Metroland and Fellow Traveller. Christian Seidel is producing. Josh Lacey has written the script.
The film is scheduled for release in the UK and internationally in autumn 2000.