“WHAT am I vain about?” In an upmarket London hotel room, roughly halfway between Whitehall and the River Thames, Jack Lowden is doing me the courtesy of appearing to take the question seriously.

“I wonder if I’m vainer in work or in life? I don’t know. There’s a natural presumption that we’re all vain because we’re actors and we’re all terrified about what we look like on screen. I’ve hit a place recently where I’ve played a couple of parts where I can go, ‘It doesn’t matter what I look like.’ It’s really liberating.’”

Says the handsome 28-year-old actor, I hear you say. Clean shaven, Polo-shirted, Scottish accent still happily intact (note to the reader: in what follows every time you see the word “do” hear it as “dae”, “ain” for “own”; he’s also the only interviewee I’ve heard use the word “spraffed” and said “That’s shan” to me in conversation), Lowden is chatty, animated and, as you may have noticed, politely dodging the original question.

But, really, if anyone deserves to be all puffed up around about now it might be Lowden. A couple of years ago he first really came to prominence when he turned up in both the lead role of Mark Gill’s small but rather sweet Morrissey movie, England is Mine and as one of the Spitfire pilots (the one who wasn’t Tom Hardy) in Christopher Nolan’s widescreen 70mm epic Dunkirk.

Right now, he’s got another double header lined up. Triple header, actually. Last month he turned up in the BBC drama The Long Song (still on the BBC iPlayer) and at the start of March he’ll be seen in Stephen Merchant’s directorial debut, the wrestling comedy-drama Fighting with My Family, opposite Merchant himself, Florence Pugh and the Rock.

But today he’s talking about the historical drama Mary Queen of Scots, in which he plays Lord Henry Darnley opposite Saoirse Ronan in the title role. Director Josie Rourke’s film is a striking period piece that takes the odd liberty with history (it suggests that Mary did meet her sister Elizabeth, the English monarch) and benefits from a suitably fierce performance from Ronan (if Beyonce did Scottish medieval royalty …)

Why did Lowden want to get involved in the first place? “The story of Mary. I grew up not knowing enough about her, really not knowing anything about her at all. She’s almost relegated to this Bonnie Prince Charlie-esque kind of figure. We’re very good at doing that in Scotland, making them romantic slash tragic, you know … There were so many things that I was completely unaware of.

“I’m just glad it got made. Anything about Scottish history. I’m so obsessed with our country’s history, have been since I was a kid. And I think growing up where I grew up on the border you sort of become even more aware of our history because it’s right up against the other country, so anything made about us I’d love to be doing.”

What’s his take on Darnley then? “He’s one of those characters who is an absolute pleasure to play because he’s never boring. He’s described as the ‘lustiest man’ Mary ever met. One of the greatest things Josie said to me was, ‘Darnley just looks like he wants to put something in his mouth in every scene.’

“He wants to consume all the time. He’s an addict, certainly to alcohol, certainly to men and women but mainly to attention and affection.”

Watching the film, I tell him, I did wonder if there were ever times shooting it where he felt a bit intimidated by how good Ronan is in it. Were there moments when you thought, ‘Bloody hell, I need to up my game here’?

“I’ve been lucky enough in nearly every job I’ve been in where I’ve been opposite someone where you go ‘bloody hell, it’s that person.’ But yeah, I’ve worked with a lot of brilliant female actors. Lesley Manville is my hero. In my opinion she’s the best actor of her generation just like I think Saoirse is of hers, so to have worked with them both …

“I’ve learnt so much from Saoirse, from her complete ease on a film set. It’s like her living room. It’s amazing.”

In December newspapers started to report that he and Ronan were an item off-set too, though he’s too much of a gentleman to confirm such stories. (When I ask if he has a significant other he says, “It’s not my favourite thing to talk about, but, yes, I do have one and it’s fantastic and it’s good fun and it’s been a really good year.”)

Read More: Alison Rowat reviews Mary Queen of Scots

What, I ask him, has been your best day on a film set? Maybe, he says, the day he got to fly a Spitfire. “Yeah, we went over the Channel itself in three Spitfires with an Imax camera on the wing and we were swooping and dooping and we flew into British airspace. That was surreal.

“It was more surreal because you’re in a cockpit on your own. There was no music going, just this brrrrrrrr,” he says, imitating the sound of the engine with a satisfyingly Caledonian rolling of his Rs. “It was like sitting inside a washing machine.”

That was a good day, he says. “That and getting to work with Stephen Merchant because he’s one of my heroes. I grew up listening to the Ricky Gervais show on audiobooks, so I grew up with him in my ears. So, to actually sit in a scene with him was bizarre.”

You do feel that right now Lowden is just the right role away from being the next James McAvoy (his role in the upcoming Al Capone movie Fonzo, again alongside Tom Hardy, might help in that regard). In any case he’s come a long way from amateur dramatics in the Scottish borders.

Lowden grew up in the village of Oxton. His father worked in the Bank of Scotland, his mum ran an art gallery for a while and they both encouraged Lowden and his brother Calum in everything they wanted to do, whether that was Irish dancing or ice hockey.

It’s fair to say that both Lowden and his brother are high achievers; Calum (who, strangely, has also been linked with Saoirse Ronan) is currently first soloist with Swedish Royal Ballet. Lowden puts any success down to his parents.

“I have the most incredible parents,” he says. “The most unbelievably supportive and self-sacrificing parents anybody could ask for. Me and my brother literally owe everything to them.”

Calum, he says, was the outgoing one. Lowden, hmm, not so much. “People say it all the time about themselves, particularly actors, but I was unbelievably shy. I was painfully, cripplingly shy, just sort of scared. Scared of doing things.

“I would like to say acting brought me out of it. It didn’t because I started acting when I was 12, 13 in amateur operatics and youth theatres, but I was terrified into my late teens. I was more comfortable on stage than in real life.”

When you say terrified … Terrified of what? “Everything. Talking to girls. Talking to boys. Talking to strangers. Getting up and talking in a classroom. Getting involved in any confrontation. I was never in a fight in my life as a kid. Never threw a punch.”

The solution to fear was experience, he says. “What I’ve loved about getting older is how you sink into yourself. You just cross things off. ‘Actually, I don’t need that.’ That’s massively helped me with my work.”

As noted before, says the handsome 28-year-old.

I wonder has the actor grown up too? “No, the actor is still the same. I’ve just finished a play. I hadn’t done a play for about four years and I noticed a couple of times thinking, ‘God, I did the same thing when I did am dram.’

“And I love that. The skills are in my body. I don’t have to think about it purely because of back then. I would hate for it to feel different.”

You once said, I remind him, that you’d like to play a part close to yourself, so you could play with all the things you hide in real life. So, what are you trying to hide, Jack?

Nothing he’s going to tell us, it seems. He talks about those moments you are on a bus or on the Tube and you want to say something about what’s happening and it’s only when you’ve got off does the pithy thing you really wanted to say come to you. “What I quite like about acting is that all that stuff is given to you and put in a better way than you could.”

That said, he wonders if temperament might be something he could expose more.

“People’s temper is something we literally temper all the time out of politeness and social etiquette. I would like to play a part where the temper comes out more.”

Because you’re really a nasty, temperamental so and so? “No. I’m impatient. I have a massive streak of impatience that both drives me and can drive other people mental in the way, I think, impatience always does. My impatience is probably the thing I try to hide most.”

Really, in the scheme of things, Jack, it’s not a massive failing. “It’s not,” he accepts.

I mean, you could have told me you were a serial killer in your spare time.

“Well, there’s always time,” he says laughing

Are you an optimist or a pessimist, Jack? “I think I’m a romantic pessimist. I know that sounds like a lot of w***, but I don’t think I’m a full-out pessimist. More like a romantic pessimist.”

Well, there’s a lot to be pessimistic about the world at the moment. “I seem to have grown out of global issues and more towards local issues,” he says. “Maybe it’s because you can do more about them.

“I used to watch the BBC rolling news. I used to have it on in my flat. I don’t watch it any more. I don’t watch the news any more. I’ve become a lot more localised the things I care about. I get my mum and dad to send me the Southern Reporter and the Border Telegraph whenever they can.”

This year Jack Lowden would like to move back to Scotland. Edinburgh preferably. “I feel like there’s something kicking off up there and the announcements about the studio have been brilliant because … it was just embarrassing. I totally understand and appreciate that it isn’t like putting a garden fayre together but when we get trickledown spraffed at us, a studio really had that. It really does.”

More Scottish films would give him the chance to act in his own accent. “Americans and English actors get to. All these period films over here and gangster films in America. Pacino and DeNiro all got to use their own accents. It’s a lot of fun being in accent, but I just feel there’s more that I can tap into my own accent.”

If you were to give Jack Lowden a day off, he says, he’d spend it at London's Imperial War Museum. He has started collecting maps and when it comes to work, really, more than anything, he wants to tell more Scottish stories. Any in particular?

“Bonnie Prince Charlie for sure. I’d love to see that properly made. He was just a loon who hijacked the Scottish people. After Culloden tartan was banned, Gaelic was banned. It was a precursor to the Clearances.

“And he got on a boat and went back to Rome and spent something like 17 years sat in parlours and bars, talking nonsense about how he almost took back the British throne. A whole culture was kicked into the grass because of him and so I’d love to see it make like that and not just make him a romantic figure.”

Casting directors, on your marks.

Mary Queen of Scots (15) is in cinemas from Friday. Fighting with My Family is released on March 1.