Iron Lady star Meryl Streep has criticised prime minister David Cameron for his response to the movie. Mr Cameron had suggested the biopic about his predecessor Margaret Thatcher was disrespectful because of its portrayal of dementia while the former British leader is still alive. In an interview with BBC Radio 4, he praises the Hollywood star's portrayal, but added: "You can't help wondering, why do we have to have this film right now?" However Streep, who plays Thatcher in the movie, hit back, claiming it is more offensive to suggest the film should have been delayed until the former leader was dead. She noted: "What about him saying on the radio that people should wait until she is dead? How must that make her feel? "It's because its mental frailty she is afflicted with that is what terrifies us most." Streep added that no-one would have batted an eyelid about the film if Lady Thatcher had something wrong with her lungs. Find out about dementia care and support services at Barchester care homes.