The production notes of last week’s eagerly-awaited release The Iron Lady, chronicling Baroness Margaret Thatcher’s life and career, feature a detailed interview with Meryl Streep, whose phenomenal performance in the title role has brought her to the cusp of winning her third Oscar. These are some excerpts from the interview in which she talks about the challenges of the role.

I don’t know if people will revise their opinion of her policies, but at least you’ll have an understanding of the pressures that came to bear...

What was your initial response when director Phyllida Lloyd approached you?

I was immediately interested. There aren’t many women leaders; there aren’t many film-makers who are interested in what it means to be a woman leader.

To think about the barriers that Margaret Thatcher broke through to become the leader of the United Kingdom was to put yourself in the head of a woman in the late 1970s, when she really emerged as the leader of her party.

She entered a boys’ club – an upper class world – and grabbed it by the scruff of the neck. Regardless of one’s politics, that’s a significant achievement...

Just walking into the first day of rehearsal was incredibly daunting because there were all these wonderful British actors and I was the only woman in the room and I sort of had the feeling Margaret Thatcher must have had when she walked into the Conservative party meetings.

The days that we were recreating parliament were very interesting because how one dominates a room, how one pulls a listening audience in to persuade them of some matter of policy is something we still struggle with as human beings.

Margaret Thatcher really did break ground in that she showed a way in which a woman could be a leader; she didn’t have a problem with how to lead, and so in a way, men didn’t have many problems knowing how to follow.

I think when women are uncertain how to lead, or they’re worried about how they’re perceived or about losing femininity, their leadership skills suffer.

You play Margaret over a span of 40 years; that must’ve been an incredible challenge.

It’s a challenge to play someone over 40 years, but once you reach my age, you still think you’re 20, so it isn’t that much of a problem; you still think, in some part of you, you are the same person you were at 16 or 26 or 36 or 46 or 56. So, you know, you have access to all the people and all the ages you’ve already been; it’s the great advantage, if there is one, to getting older.

It was a wonderful opportunity. Usually movies just locate you in one specific time, but this was a movie that got to look back on a whole life and that was really thrilling to try to do.

Do you think people will come away from the film revising their opinion of her?

I don’t know if people will revise their opinion of her policies, but at least you’ll have an understanding of the pressures that came to bear and why she seemed in her time to present an answer, and then why that answer was rejected; I think you’ll come to see that, at least.

At the heart of the film is this love story with Jim Broadbent beautifully playing Denis; himself a fascinating character...

Denis Thatcher is a character who in the public eye had been characterised as a sort of buffoon. And the outline of the public version of who he was was one aspect, but we knew that Jim would anchor this character in something that had depth and understanding of his own comic persona. What his own sense of humour did to leaven both of their lives and how important that is in a relationship to have somebody who’s willing to bring the fun.

I think that a large part of the reaction to Denis was because his position destabilised a lot of people. It was upsetting to see a woman head of state and then, “what’s he? Mr Mrs or something? I don’t know; the first lady? What is he?”

We’re in this stage in our human evolution where we’re getting used to how to make accommodations for these new positions of the genders. And I think he was lampooned, but he didn’t seem to wear it with resentment and that was a really remarkable thing.

I know Jim Broadbent came in with a bias very much against Margaret Thatcher and her policies. And as we grew to be an old married couple, I think he shifted not in his assessment of her reign or what she did politically, but I think he may have made an accommodation for who she might have been.

What was the best part of making this picture?

The best part of making the picture was really the opportunity to look at a whole life. Sometimes it’s overwhelming how big a life can be; how crammed with events that seem momentous at the time.

It’s an unusual ambition for a film to aim a whole movie to the end. Usually, you aim at the apogee, you aim up. And we are looking at the distillation of what it means to have a gigantic, big, full life and then to watch it subside. I mean, it’s a poem, right?