Ten leading members of Britain's ruling Conservative Party--including former Prime Minister Edward Heath and former party chairman Norman Tebbit--have turned down invitations to Thursday's London charity premiere of Sir Richard Attenborough's "Cry Freedom." The film about black South African activist Steve Biko, which opened in the United States and Zimbabwe earlier this month, is an indictment of South Africa's racial policies. It has been criticized for oversimplifying South Africa's apartheid policies. The British politicians who turned down the invitations insisted that they did so individually and not as part of an organized boycott of the film. Attenborough, however, told British newspapers this week that he found it "extraordinary and too much of a coincidence" that so many had declined.