In the seven months since its world premiere at the Toronto International Film Festival, the conversation surrounding William Olyroyd and Alice Birch’s Lady Macbeth has drawn primarily from the project’s feminist credentials: for all intents and purposes the film’s protagonist – Florence Pugh’s Katherine, described in the official Twitter bio as a ‘headstrong woman’ – is a thoroughly modern lady, a character rarely observed on screen in the context of the period in which the film, a reimaging of a Russian novella, is set. The pair’s ‘colourblind’ casting, for a production placed in the 19th century, has elsewhere produced similar fanfare.

Central to the former however is the striking blue frock Pugh dons on screen and in the accompanying campaign, currently doing the rounds throughout London’s tube network: initial junket emails offered invitations to dress up ‘Lady Macbeth style’, while the original gown was brought out at a ‘Nasty Woman’ panel discussion that prefixed a recent screening; the piece’s elaborate physical restrictions serving as a metaphor for Katherine’s own incarcerated existence.

When I meet the actress, who starred opposite Wonderland cover star Maisie Williams in 2014’s The Falling and subsequently picked up the BAFTA Breakthrough Brit award at last year’s ceremony, the heavy fabric is gone, swapped for a lightweight snakeskin number she later informs is a Zara favourite. It’s a few hours since a stint on the BBC’s prestigious Woman’s Hour – an experience for which she was “so, so nervous; we had a good chat, especially after all the politics, I think they needed something lighter” – and she’s in full force as we talk about a film that is, in actual fact, anything but light.

What attracted you to the role of Katherine?

Katherine is this fantastic young woman who essentially doesn’t like being told no, and her fierceness struck a chord with me because I think I am quite similar. She goes against what was the norm at the time and shocks people in the film, as well as people watching the film, I think that’s a pretty cool character to at least attempt.

And was it easy to relate to her?

You know, she is a very modern woman, in 1865 all the things that she does and the way that she lives are things that we recognise as people on screen, and that’s what really drew me to her. Every time I turned the page she was doing something bigger and better than the last and it’s very rare – I was 19 when I got the role – and it’s very rare that a 19 year-old unknown actress would be able to do that. She’s her own force and I couldn’t really understand why I wouldn’t want to play her

So what research went into the part?

Most of it happened when we were up there rehearsing. Obviously I read the script a hundred times, but I like to keep my work quite instinctive, if I overwork something it basically becomes nothing and I look like a sponge on screen, so I like to keep things fresh. Most of the preparation came out of wearing a corset and wearing a dress, we did a lot of rehearsal time when me and Cosmo (who plays Sebastian) would have to wrestle or fight or do any of the movement scenes which would be fine, up until I got into the corset; I just couldn’t move the same, you can’t speak the same, you can’t sit the same, you can’t walk the same, it’s all completely different. So, getting into that corset was the biggest eye opener, what it essentially does to a woman is it makes everything smaller, you are essentially imprisoned by your own clothes which was the complete point of that type of clothing. For me, I was like wow, Katherine must have hated this as much as I do. So yeah, it was really helpful.

You’ve been quite vocal about the corset. What was the biggest surprise you encountered?

Well, they made all of my clothes and then they made me a corset from scratch. So obviously you can only get into the dresses if you are wearing a corset and obviously, they work for the corset but not for you, so that was interesting – you can only wear your clothes if you’re tightened in, like that’s such a bizarre thing. So we were always in them when we were trying on dresses or doing fittings, when we got my corset we had to test out all the big moves to see if I could move, which evidently I couldn’t.

The most fascinating thing, of course it makes so much sense now, is when you are wearing the corset your body is obviously shrunk, it’s smaller, so if you eat you end up using space you use to breathe. We all know the stereotypical idea behind the corset, like we’ve all seen that scene in Pirates of the Caribbean when Keira Knightley falls off the side because she can’t breathe, it is legitimately like that. If you eat too much, you suddenly can’t breathe, it’s bizarre. It does exactly what it was designed to do which is to make the woman smaller and it makes them quieter and it makes them less energetic. So I used that, I made sure that when she was happiest she was in her nightie or naked or in a dressing grown, and that is something that we all recognise as being modern, women dressing for comfort, which I find hilarious.

Your face is everywhere. That must be odd?

Oh my god, completely bizarre. My friend was on a boozer in Amsterdam and sent me a selfie of them and my poster. It’s really weird, it’s amazing though because it is a project I really support and want to talk about it, I’m really proud that it got this far, it was such a small team with such a small amount of money, and to see it now around the world… It’s kind of what you hope every film will be like.

Were there any specific stories that inspired you when you were younger?

I watched a lot of films when I was younger, it was a big feature with my family, understanding performances (we all do it, all my siblings) so recognising interesting qualities or talents is something we all like watching. In terms of inspiration, it’s funny, it’s not like I watched a specific big Disney film and said ‘ah I want to be her’, I was always interested in the smaller side of film and the realness of scenes; I think that stays with me now. I would much prefer to represent us as people as opposed to something that we don’t recognise at all, and I think I knew that as a kid, that I wanted to do real stories.

You’ve been touring Lady Macbeth for a while. What sort of things have people specifically picked up on?

Lots of people abroad, like in Spain, they didn’t like the ending, obviously, and some peopled walk out.

That’s a big deal, to walk out of a film.

I also love it, I think it’s really cool that a film can make you do that. Also I find it fascinating that up until that point you were totally cool with her doing those awful things, but now it’s a little bit too violent they are like ‘no I’m going to leave’. I think the reason people get so shocked then is because they find shock in themselves, the fact that they have supported her until that point and now that it’s a little bit too far, they are like ‘oh well I didn’t like her anyway’ but that’s not true, and I think realising that in yourself as well is a little bit like ‘woah, she manipulated me”.

How, if at all, has your BAFTA win affected your work?

It has put me next to a very important word which is BAFTA, and I think that is the coolest part of it. People not only now know me because I’m connected to these films, but it means I’ve got that recognition. I’m on a list that has been decided by incredible people and that was a really wonderful present to receive, before the film even came out. I think it’s given me a little tick of approval.

Like a blue tick (sorry).

Literally, literally yeah it is, and it says ‘we think you’re doing alright’, and it’s just such a wonderful thing to receive from BAFTA.

So what would be your dream project?

I really really want to work on some sort of western. Honestly, I’m a fan of always changing it up, like I don’t want to play the same part twice. I love to be scared by my characters, I love to feel terrified because that excites me, that they are so big and so great that I’m worried. I’ve done Katherine, she was epic and I’ve just played a wrestler, and so I think now I want to play some sassy woman with a gun.

Do you have a favourite western?

For me, I just love the idea of dirty characters. I love earthiness and realness and I love the idea of being a bit grubby and having mud under my nails, knowing how to shoot a gun. I think that’s awesome.

So returning to Lady Macbeth, the film’s release has obviously come about at quite a significant time, in terms of where we’re at with women’s rights.

Totally, I think the reason why it’s striking such a chord is because it’s not expected. Especially now especially with women uniting around the world it’s like ‘oh this girl back then was doing it too’, it’s the fact that what is happening now is seeping into art and I think that’s very cool. Because we’re modern doesn’t mean that women didn’t have a voice, women could have had a voice back then except we’ve seen loads of period films where women don’t have a voice and that’s why it’s refreshing to see, it’s like ya ya sisterhood.

Lady Macbeth is our nationwide on Friday 28th April. Applications for the 2017 Breakthrough Brits are open here, now.