British PM Cameron criticizes Thatcher film's timing LONDON (Reuters) - British Prime Minister David Cameron on Friday criticized the making of a film showing his predecessor Margaret Thatcher as a vulnerable elderly woman. "The Iron Lady," featuring American Meryl Streep in the main Thatcher role, opens in British cinemas on Friday. Cameron praised Streep but suggested the film should not have been made while Thatcher was still alive and suffering from dementia. It's a fantastic piece of acting by Meryl Streep. You can't help wondering, why do we have to have this film right now. It is a film much more about ageing and elements of dementia rather about than an amazing prime minister," he told BBC Radio 4. "My sort of sense was a great piece of acting, a really staggering piece of acting, but a film I wish they could have made another day," he added. The film shows Thatcher, now 86, as a confused and lonely old woman looking back on moments from her momentous but highly divisive political career [ID:nL6E8C536W]. Thatcher, Britain's first woman prime minister, ruled from 1979-1990, leading Britain into war with Argentina over the Falkand Islands and taming powerful trade unions at home. Cameron's reservations are shared by other members of his Conservative Party, which Thatcher once led and which currently heads Britain's coalition government. "Meryl Streep should probably get an Oscar for an amazing portrayal (but) there was too much of a concentration on Lady Thatcher's dementia and not enough on her life story, her achievements," Conservative lawmaker Louise Mensch told Reuters. Former Conservative politician Michael Portillo told the BBC he "felt uncomfortable" about scenes highlighting her illness. One-time Thatcher rival Michael Heseltine, who once challenged her for the Conservative leadership, took a similar view. "I think Mrs Thatcher was a formidable prime minister and to produce a film in her later stages of life depicting the problems of advanced old age, I find extremely distasteful," he told Britain's Daily Telegraph newspaper. Reporting by Keith Weir, editing by Paul Casciato