Meryl Streep has revealed playing Margaret Thatcher in The Iron Lady was "tough and challenging", likening it to "battle".
The Oscar-winning actress, who is already the bookies' favourite to receive an Oscar for her performance as the former British Prime Minister in Phyllida Lloyd's controversial biopic, confessed it wasn't the easiest of movies to make.
"I went into battle every day on this movie, at times I felt like a marine," she told the Daily Mail.
"I won't deny it was tough and challenging - and highly emotional too.
"This is a woman familiar the world over, and portraying her on screen, especially when her health is failing, requires both accuracy and sensitivity."
The 62-year-old added: "What I found toughest is the contrast between a woman with dementia and this tough female icon of yesteryear. It reduced me to tears."
The film, which depicts the life of Mrs Thatcher, has already come under fire for the way it shows her suffering from dementia, but Meryl insisted she hasn't done her any wrong: "I think if a movie like this is done in the right way, it's OK.
"We don't diminish her or her achievements in any way, and the fact that someone as strong and as empowering as Lady Thatcher can be affected by dementia underlines what we are saying all the way through the film - that she is human, mortal and vulnerable."
She added: "I wouldn't want to show her in a way that is disrespectful."