Though Meryl Streep is winning praise for her turn as former British prime minister Margaret Thatcher in The Iron Lady, the biopic itself is receiving criticism, including from current U.K. leader David Cameron.

Cameron and other Conservative Party colleagues have blasted producers for poor timing and insensitivity in releasing a film that depicts Thatcher's dementia while she is still alive.

"It's a fantastic piece of acting by Meryl Streep, but you can't help wondering, 'Why do we have to have this film right now?'" Cameron told the BBC.

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British Prime Minister David Cameron, seen in Maidenhead, England on Thursday, criticized the depiction of a frail Thatcher suffering from dementia. (Kirsty Wigglesworth/Associated Press)

"It is a film much more about aging and elements of dementia rather than about an amazing prime minister."

Set in contemporary times, The Iron Lady cuts between scenes of a frail, elderly Thatcher and her memories of her political ascent and time in power as the steely leader of Britain from 1979 until 1990.

Other politicians have also blasted the drama, with former foreign secretary Douglas Hurd describing the film as "ghoulish" and former Conservative Party chair Lord Tebbit saying Thatcher was never the "hysterical, over-emotional, over-acting" woman depicted in the film. Journalist and former newspaper editor Charles Moore, who wrote a biography of Thatcher to be published after her death, called the film "unkind."

Movie critics have praised Streep's performance, though The Iron Lady itself has garnered mixed reviews.

Director Phyllida Lloyd defended the film during its preview screening in London this week.

"We all felt that a portrait of somebody who is experiencing a failure of strength and health and forgetfulness is not a shameful thing to put on the screen," Lloyd said.

"It's something that Meryl and [screenwriter] Abi Morgan and I felt was a really worthwhile exploration."

Britain saw significant economic, social and political change during Thatcher's time in office and she remains a polarizing political figure. England's war with Argentina over the Falkland Islands took place during the Thatcher era, as did the fall of the Berlin Wall and and the collapse of Communism.

Known for curbing unions during her tenure and selling off state-owned assets, she was dubbed The Iron Lady by Soviet journalists for her stern resolve.