Meryl Streep's transformation into former UK Prime Minister Margaret Thatcher might be her most startling yet, but the actress said that arriving on-set helped her step into the role.
"For me, as an actor, just walking into the first day of rehearsal was incredibly daunting because there were all these wonderful British actors, I think there were about 40 or 45 of them, and I was the only woman in the room," Streep said in an interview provided by The Weinstein Company. "I sort of had the feeling that Margaret Thatcher must have had when she walked into the conservative party."
The movie, based on the nickname of the 85-year-old Conservative leader and Britain's first and only female prime minister, depicts how Thatcher "smashed through the barriers of gender and class to be heard in a male-dominated world," the production company Pathe said in a statement.
"All those gents were so great to me and welcoming in this territory where I really don't belong, as the interloper, the American," Streep explained. "But in a way, I had courage to play Margaret Thatcher because she was an interloper in this Oxford, Etonian conservative party into which she marched, undaunted and I thought, 'Well, if she can do it, I can do it!'"
Filming on "The Iron Lady" began on January 31 and the movie is set for release on December 16 in the United States and on Jan. 6, 2012 in the United Kingdom. Its director is Phyllida Lloyd, who directed Streep in the 2008 film "Mamma Mia!"
Thatcher served as the UK prime minister between 1979 and 1990. She maintained a tough stance against communism, led the Conservative party in its battle against the nation's trade unions and helped secure the 1981 release of 52 Americans who were held hostage for 444 days by Islamic militants in Iran.
In 2008, it was revealed Thatcher, who survived an assassination attempt by the Irish Republican Army in 1984 and several small strokes in 2002, suffered from dementia.
"'The Iron Lady' is a film that circles Margaret Thatcher's life and issues around a woman leader like that," Streep continued. "I was already, immediately interested because there aren't very many woman leaders, there aren't filmmakers interested in investigating what it meant to be a woman leader. So I was really very interested."
The film is set in 1982 and tracks Thatcher in the 17 days before the two-and-a-half-month-long Falklands War, whose victory spurred increased approval ratings that ultimately helped lead her to win a second term.
"Margaret Thatcher really did break ground in that she showed a way that a woman could be a leader," Streep said. "It was really interesting -- she didn't have a problem with how to lead and so in a way, men didn't have a problem with knowing how to follow."
Streep has won two Oscars and has been nominated for 16 of them. Aside from "The Iron Lady," the actress is preparing to star in the new comedy "Great Hope Springs," her spokesperson confirmed to OnTheRedCarpet.com. The movie is directed by David Frankel of "The Devil Wears Prada," which earned Streep an Academy Award nod.
"Great Hope Springs" is set for release in 2012, depicts a middle-aged couple who undergo counseling after 30 years of marriage. Others attached to star include Philip Seymour Hoffman and James Gandolfini of "The Sopranos."
Streep recently an honor from the Kennedy Center for her contributions to American culture through the arts. Other honorees include singer Neil Diamond, Broadway singer Barbara Cook, cellist Yo-Yo Ma and saxophonist Sonny Rollins.
Check out the trailer for "The Iron Lady" below.