IN a hotel room in Edinburgh Mike Leigh is considering the notion that evil exists.

It’s a question prompted by the reason he’s in town; his historical film Peterloo, about the infamous massacre in 1819. What I want to know is would he consider the actions of the magistrates, yeomanry and cavalry that day evil?

“Well,” the bearded, Buddha-bellied 75-year-old director begins in the tone of a slightly exasperated teacher, “let’s approach the question like this. Do we believe that good exists? If it does, what is it? It’s people that want to help other people, care for other people, do the right thing, make things better for other people.

“Now, if we accept that that exists, then we have to ask ourselves does the opposite exist? There are people who squash beetles and kill flies when they don’t need to, people who torture cats and children, people who do beastly things to other people for a whole variety of reasons. And if one of those reasons is fear and paranoia – which is certainly what motivates the authorities in one form or another as depicted in the film – you could argue that that is a manifestation of evil.

“As a healthy atheist,” he concludes, “I think there are good people and there are bad people. And there are shades.”

Peterloo marks something of a high watermark for Leigh. The director best known for his domestic dramas Secrets and Lies and Happy Go Lucky, has been cultivating a side-line in historical drama this century, in films like Topsy Turvy, Mr Turner and even Mr Drake.

Peterloo is his most expansive, expensive film yet, a lengthy and inevitably controversial epic. Because you can’t make a film about British history that veers away from Kings and Queens and not expect Daily Mail headlines.

For those who aren’t aware of the facts (and that does seem to be most of us), on August 16, 1819 around 60,000 people (some accounts suggest the number was much higher) gathered in Saint Peter’s Field in Manchester to demand parliamentary reform in the wake of chronic hunger and unemployment in the wake of the Corn Laws.

After the local magistrates read the riot act, local yeomanry – reportedly drunk – and then cavalry attacked the crowd with sabres drawn, killing an estimated 18 people (including four women and a child) and injuring nearly 700 men, women and children.

“It was chaos,” Leigh suggests. “People say it was a battle. It wasn’t a battle. A battle is two sides which are potentially equally matched who know what they’re doing and know they’ve got to fight each other.

“They had no justification for bringing in the troops They don’t wait, they jump in and it’s chaos. It’s a mess. That’s my take on it. That’s anybody’s take. It was a complete shambles and that’s why it was the disaster it was.”

The fact is Peterloo – which led to the establishment of the Manchester Guardian and Shelley writing The Masque of Anarchy – is not as well known in our nation’s story as it could be. The historian Dominic Sandbrook, writing in the aforementioned Daily Mail has already suggested that in the grand scheme of things Peterloo was “barely a pinprick.”

“Yes, he did write that,” Leigh says. “And it is his inalienable prerogative to write such garbage. That’s all I have to say about it.”

That’s a typically Mike Leigh response. He has short shift for those he disagrees with and for stupid questions (I do have a few).

There’s a self-confidence verging on the bullishness about him. But then with 13 films and 11 TV films on his CV (including Abigail’s Party and Nuts in May, the dramas that made his name) maybe he is entitled to all of that.

One of the pleasures of Leigh’s historical films is that they muddy up the received image of Leigh as the purveyor of muddy domestic dramas (itself a rather lazy cliché). They are also more amenable to making a case for judging Leigh as a film-maker. (Peterloo even has drone shots!)

The truth is, even his most domestic dramas, although modest in their mis en scene, can be quietly effective and visually imaginative. In Life is Sweet there’s a lovely sequence that shows Jim Broadbent walking through a kitchen which is both an exploration of space and character in the same minute of screen time.

When people talk about Leigh they always talk about his semi-mysterious “process.” He works with actors to construct characters and situations before he writes a script. The fascination with the process – partly because Leigh doesn’t want to over-explain it – sometimes the image-making is overlooked.

That’s harder to do with a film like Peterloo in which the spectacle is an essential part. Shot by cinematographer Dick Pope, who has worked on all of Leigh’s movies all the way back to Life is Sweet, it offers obvious visual pleasures; the Vermeer light that bathes Maxine Peake in the film’s interiors sequences, and the drone shots of men marching on the moors.

But in the end, Leigh says, he approaches all his films in the same way. “Whether you’re talking about three people arguing on a staircase in a suburban house as happens in many of my films or whether you are talking about the Peterloo massacre we’re talking about being on the ground with stuff that we make happen and looking at it and working out how to shoot it.”

If I’m honest I’m not sure that approach totally works for Peterloo. Leigh’s take on the massacre is rather sober. Good at suggesting the chaos of the day but maybe not visceral enough.

Other film-makers, he admits, would have shot it differently. “Another kind of film-maker or film eye could well have chosen to shoot all these events in a much more flamboyant or pyrotechnical way. To me, obviously, that would be both irrelevant and gratuitous and, actually, at some level – and this is my own personal view and no more than that – a kind of insult to the audience’s natural intelligence to understand the thing in a truthful, ordinary, real way.”

What you are saying is you have your own cinematic language? “Yeah, and it comes from always letting the action and the integrity of the action dictate how you look at it and how you shoot it basically.”

I don’t mean to be ageist Mike, I start to say, but you’re 75 … “Yes, ‘I don’t want to be ageist but you’re 75,’” he points out laughing. Umm, yes. What I was going to ask was how is it making films in your eighth decade?

“Look, here’s the thing on this. We film-makers, unlike novelists, painters, poets, potters and composers, we don’t work by ourselves. It’s a team thing and if you’ve got a very good crack team which I have it makes it possible to do it.

“There are certain things I can’t do. I’ve got an artificial hip. I can’t sit on the ground anymore but that’s all right. There are ways and means.

“And besides, making movies and making this movie no less than any other is great craic. It’s not for me to say but my films are, if nothing else, famous for what good spirit there is. People don’t behave badly, and they don’t fall out and they don’t muck about.

“There are exceptions obviously, but they are harmonious. There’s no room for actor nonsense and there’s no room for ADs [assistant directors] behaving like fascists and all that stuff which you do get on movies.

“Thus, if you happen to be 74 as I was when we were filming,” he adds, eyebrow suitably raised, “or 77 which I shall be when I make my next film, touch wood, it’s very energising.”

You still enjoy the experience? “Yeah, it’s great. We spend six months working with the actors and doing all that. I like that the least because you’re just preparing, you’re just mixing concrete or preparing the ground. You’re not actually doing the thing itself.”

It’s the shooting rather than the prep that you like then? I had always assumed …

“Everybody always does, but they’re wrong.”

Peterloo is in cinemas today. Read Alison Rowat’s review in tomorrow’s Herald Magazine.