It’s rather strange, swapping the craziness of the Edinburgh’s Royal Mile at festival time for the preternatural quiet of the Scottish parliament in early August: like being thrown out of a party. But never mind. One star performer, at least, is in the vicinity, in the form of Ruth Davidson, the redoubtable leader of the Scottish Conservative and Unionist party. Davidson has already had her break – in Spain, where she “read a book a day, and drank lots of funny coloured drinks”, but nevertheless checked her emails every two hours – and now she is back, bridling slightly at the very idea she might do anything other than work through the dog days of summer.

“I’m a workaholic,” she says, flashing me one of her startling megawatt smiles (bright as they are, they do not always connect to her eyes). “Politics is funny. It’s quite a short life span. I’m the third Conservative party leader [in Scotland] since devolution. The other two lasted between six and six and a half years each; I’m already four and a half in. You do it at 100 miles an hour, but you don’t do it for ever. You have to keep the forward momentum, or there’s somebody at your heels looking for your job.”

'Lots of people are a bit annoyed at Sturgeon. Fair enough, she's a lifelong nationalist… but that was pretty cynical'

How far ahead can she see? “Well, there are plenty of measurables: electoral cycles rather than years. We’ve got lots of staging posts in Scotland. New powers in terms of taxation came in April, there’ll be more next April, and more in 2018. Then there’s Article 50 to be moved on Brexit, so we’ve got a two-year clock on that.”

How does she feel, now, about Brexit? In particular, how does she view the current position of Scotland’s first minister on it? (Nicola Sturgeon seems to be rowing back on her suggestion that Brexit increased the likelihood of another independence referendum, Scotland having voted to remain in the EU.) On the subject of the vote to leave itself, Davidson, for all that she made such a good case for Remain, is predictably bullish; 17 million people can’t be ignored, and everyone must work to make best of the “opportunity” that lies ahead. But naturally, she thinks it’s wrong to suggest, as Sturgeon appeared to, that one referendum was just what she calls a “cipher” for the other, not least because – to take just one example – some 400,000 SNP supporters voted for Brexit.

“There are lots of people, tens of thousands of them, who are actually a bit annoyed at the way in which Nicola Sturgeon has tried to use this,” she says. “Within three and a half hours of the last vote being announced [after the EU referendum], Nicola Sturgeon stood up at Bute House and said that she’d already instructed Scottish government officials to draw up the legislation for a second independence referendum.” She sniffs. “I think people saw it for what it was. Fair enough, she is a lifelong nationalist. But this was the first minister of a country acting, not as a first minister, but as [first and foremost] the leader of her political party. That was pretty cynical.”

Facebook Twitter Pinterest Ruth Davidson, centre, with the Scottish Green party’s Patrick Harvie, Scottish Labour leader Kezia Dugdale and First Minister Nicola Sturgeon during the EU referendum campaign in Edinburgh. Photograph: Jeff J Mitchell/Getty Images

Polling suggests that, post-Brexit, fewer people now want independence for Scotland. Why does Davidson think this is? “People can see the issues Brexit raises. If you stub your toe, you don’t then shoot yourself in the foot. You’re not about to leave another union, which is worth four times more in terms of trade. The economic case for independence is worse now than it was a few years ago, and the case that the SNP tried to run – that you can have a big constitutional change without it having any large economic impact – has been blown out of the water. We’ve just seen it with Brexit. That doesn’t mean that the SNP isn’t wanting to whip up nationalist fervour. But they know as well as anybody that if another referendum is held, and they lose it, then it’s done. The only template we have is Quebec, where a second referendum was lost by only about a point, after which support for independence went off a cliff.”

Meanwhile, in London, there is a new prime minister to deal with – though for God’s sake, don’t make the mistake of celebrating aloud the fact that another female politician is running things. (“Some of us have been in charge for a while, and no one noticed,” she says tartly, when I do this.) Davidson was a supporter of Theresa May, and knows her much better than she did David Cameron – “DC”, as she sometimes calls him – when she first became Scottish leader.

“We have got, I think, a good relationship,” she says. “I really like her. I know her media persona is quite reserved, but she’s got quite a quiet wit about her. I think she’ll be a good prime minister. She takes everything very seriously, and will always do the right thing. To serve through Brexit is going to be a bloody tough shift, and I take my hat off to her that she wanted to take it on.” Davidson was at No 10 the day before May became PM. “I met with both the outgoing prime minister and the incoming one for some time. In between, he was giving Theresa a tour of her new flat. Yes, it felt quite historic. One of the interesting things was, knowing Theresa relatively well, I had expected that the weight of the office would make her quite tense about what was coming, as it would for any human being. But actually, this almost the most relaxed I’ve seen her. There was a sense of serenity and calm about her, the idea that she knew exactly what she was going to do.”

Did she, though? What about (Leadsom! Johnson!) some of her wilder cabinet appointments? Or was that just a case of keeping your friends close, and your enemies even closer? Davidson thinks this is a mischaracterisation, one all too common in those outside the Tory party. “Even using words like ‘friends’ and ‘enemies’… We all want what’s best for the country. There is a sense of service and duty. We need to put in a proper shift.”

Facebook Twitter Pinterest Davidson: ‘I’m not a shouter.’ Photograph: Murdo Macleod/The Observer

Hmm. While this might well be true of May and, say, David Davis, most people would be wary of crediting Boris Johnson, the new foreign secretary, with a sense of service at this point. “He’s an interesting study. I think he knows that if he’s judged to be found wanting in this role, his political career is probably over. So there is a large personal as well as profession incentive for him to get his finger out.”

Will there be an early election? If I were May, in possession of a miniature majority and contemplating the omnishambles that is a Corbyn-led Labour party, I would be sorely tempted (and sod the law pertaining to fixed parliaments; that can be fixed). Davidson is – genuinely, I’d say – conflicted. “John Major came up to help during the referendum, and we had dinner, and he was talking about how draining it is to have a small majority in the Commons, how it gets you down dealing with your own side. He had a larger majority than Theresa, so I can see the temptation. She knows if people want to cause problems, they can do that quite quickly. I would like to think that the usual suspects might behave [now] in a different manner, but we shall see… However, it might be seen as opportunistic to hold a snap election less than two years after the last one. There is an aspect of her needing to get on with the job.” She pauses. “But I’m torn. Why not get a mandate? Labour called for an election after she became prime minister, so they can’t criticise her if that’s what she does.” Is she ready for an election? “If one is required, I will make sure the party’s ready.” Her voice is steely, completely without doubt. “We’re organised. We will do well. We will increase our number of seats.”

I remember the precise moment I decided I wanted to interview Davidson. In a newspaper, I saw a photograph of her and George Osborne. They were visiting a Scottish farm, and each of them had a shovel, or perhaps a fork, in their hands, on the end of which there was balanced a mound of something brown and stinky-looking. The then chancellor was a little closer to the camera than her, and giving the world his regular wan I’m-working-hard-to-keep-Britain-moving smile (an expression he usually wore with a high-vis jacket, though not on this occasion). Meanwhile, behind him, Davidson was pulling a much funnier face, her eyes wide, her grin on the edge of manic. It was like something out of a Carry On movie: if she wasn’t sending up Osborne, then at the very least she seemed to be sending up the photo opportunity, in both the abstract and the particular. “We’ve shovelled a lot worse, eh, George?” someone captioned it, later.

You have ‘punch the air’ moments, and you have ‘crying silently at night' moments… but you do it in your own time

“It was feed!” she says now, in the small, sterile meeting room in which we talk. “Everyone says it was shit, but it wasn’t, I promise you.” She laughs, wildly. When she stops, I ask if she knew she would be so good a party leader, by which I mean, mostly though not exclusively, that she somehow makes the vast majority of other politicians look even more weird and phoney than usual. “Well, I’m trying my hardest to be good at my job. But we’re Presbyterian here. We don’t talk about this sort of thing the way private schoolboys would.” Until she decided to seek elected office, she worked as a journalist at the BBC. Much as she loved journalism, she was tired of being an onlooker; she wanted to be what she calls an agent of change. “[I suppose] that is a type of arrogance or pride or self-regard. Whether that’s an unattractive quality or not…” She doesn’t finish the sentence.

OK, let’s turn this around. Did she ever worry – she’d only been an MSP for five seconds when she decided to throw her hat into the ring as party leader in 2011 – that she’d be bad at the job?

“There are times when you feel, oh shit, I wish I hadn’t done that, and you beat yourself up about it; and there are times when you feel desperately, desperately alone because it doesn’t feel like anyone’s helping you with the task. You have ‘punch the air’ moments, and you have ‘crying silently at night so as not to wake up the person next to you’ moments. But I guess leadership is about doing that in your own time. It’s about strength and tenacity and moral courage.”

Is she what she seems, though? How much of her jollity and relative straightforwardness is an act? “I don’t wear any masks. If I had, I don’t think I’d have been able to keep them on for five years. I’m in the media every day. I’ve never been caught out. That tells you something. Folk aren’t daft. They can tell you’re not answering the question, or if you don’t mean something.” She says that she likes people; she enjoys talking to them. But she isn’t sure about charming (my word) them. “There’s a lot of people I’ve rubbed up the wrong end, who’ve felt the rough of my tongue.” Has she got a temper? “I’m not a shouter or a thrower. I’m not tossing mobile phones around as previous prime ministers are alleged to have done. I do quiet, steely, gimlet-eyed chat. But you know if I’m fucked off with you.” She looks at her aide, who is recording our encounter; he smiles, but he doesn’t quite look back.

Facebook Twitter Pinterest Ruth Davidson with George Osborne on the Remain campaign trail in June 2016 at a farm near Galashiels: ‘Everyone says it was shit but it wasn’t, I promise!’ Photograph: Jane Barlow/PA

The national press still marvels at her near unicorn-like status as a working-class, lesbian woman at the head of a bunch of Tories. (It used to go on about her passion for kickboxing, too, though she’s long since given that up.) Is this irksome? It used to be. During the leadership race in 2011, she wanted very much not to be known only as the lesbian kickboxer (the other candidates were all defined by their jobs): “It seemed it was done to diminish me, and it was the only thing anyone knew about me.” But when she was elected, everything changed. “I got lots and lots of emails, mostly from young gay men, but from girls, too. They were really personal letters: ‘I’m not out to my parents or my school’, or ‘I am out but I found it really hard.’ Some said: ‘I always fancied politics, but I never thought I could, and it really matters to me that you got elected.’” This was a revelation. “I’d never signed up to the role model argument. If someone says I can’t do something, it just makes me want to do it twice as much. I’m cussed and dogged like that.”

She was touched. “I made sure to reply personally, and I told them about my background, and I was really pleased that none of them ever went to the papers afterwards. After that, I promised myself that if I was ever asked [about her sexuality], I would never walk away from it. That wasn’t for me. It was for other people.” Does she feel good about that decision now? “I do feel things have changed, though not because of me. I’m 37. When I was born, homosexuality was still illegal in Scotland. Now the same couples who could have been prosecuted can get married, and we’re a better country for that.” (She and her partner, Jen Wilson, announced their engagement last May.) She got vile letters too, of course, and sometimes still does get abuse on Twitter, of which she is a big user: “I have rules. I tend not to engage with people calling me all the bad names under the sun for party or policy or appearance or weight. But every month or so I do push back on homophobia. I do not have to take that, and nor does anyone.”

These days, then, she is more likely to be irritated by questions about her class than her sexuality (though I have to say, too, that she later pointedly refers to my voice as “posh”, so this cuts both ways). “People outside Scotland think that if you come from an estate, it’s either a council estate or a shooting estate,” she tells me. “I’m actually from neither of these. My parents are working-class Glaswegians, but my dad moved to the Borders [to work in a textile mill] before he had me, and when they [the mills] shut, he moved to Fife, where I lived in a normal kind of house, in a normal kind of village.” Her school was in a socially disadvantaged area, and a high proportion of its students had free school meals, but her parents were keen on education: “Books were your friends. You didn’t break their spines or rip their pages.”

Facebook Twitter Pinterest Davidson with her partner, Jen Wilson. Photograph: Matt Cardy/Getty Images

She had a serious accident as a small child – aged five, she was run over by a truck outside her house – and for a time, it was thought she might not survive; later, she had to learn to walk again.

“Probably, that [accounts for] part of my determination: being the only kid in primary school with a Zimmer frame.” Looking back, she’s amazed that she was allowed to climb trees, or play football with the boys. Given what they’d been through, her parents must have longed to wrap her in cotton wool. “But what was always drummed into us [she has an older sister, who is a doctor] was that effort was more important than results. I remember one school report. I got a two for science for effort, and a one for my results, which was the best you could get, and I got a mini bollocking for that. My mum would have been much happier if it had been the other way round.”

Her parents were thrilled when she got a place to read English at Edinburgh university, and equally delighted when, having begun her career on local newspapers, she ended up at the BBC. But they were perhaps rather less pleased when she announced she was jacking in her job and the pension that went with it to try to get elected as a Tory, and in Glasgow of all places (she now represents Edinburgh Central).

She is a capable, competent, principled woman and I believe that respect is reciprocated. But we don’t go out for pizza

“You can’t fault their logic,” she says. It wasn’t easy for her mother to see the word “lesbian” in the headlines, though she’d come out in her 20s (she won’t say how her parents’ received this news). “I’ve had to say on the phone to them: ‘Please don’t write to the Herald, Dad. I can fight my own battles.’” Davidson, however, knew that politics was her future, at least in the sense that she knew a referendum on independence was coming, and that she would have found it unendurable to stay silent as the future of her country was debated. I suppose this is another way in which she is a role model: she wasn’t old when she went into politics, but nor had she devoted her 20s to it. “I don’t know how people like Charles Kennedy did it,” she says. “Being elected at 21. How do you talk to someone about their housing benefit or school places when you’re 21?” For anybody reading this, she would like it to be known that “there is no law that says you have to be a bag carrier or special adviser [to go into politics], and people will think a lot more of you if you’re not”. Ambition didn’t come into it. “If it had been about personal ambition, there was a really strong argument that said: don’t try and lead a party that doesn’t want you as leader; spend some time on the back benches.”

What about now? Is she ambitious – or, at any rate, woman enough to admit she is? (Men, as I tell her, seem to have no problem at all with the A-word.) “There are things I want to do.” What things? Does she want to be prime minister, a job for which she was once tipped by the great sh—, sorry, feed shoveller himself, George Osborne?

“Strictly Come Dancing is on the list,” she says, confessing her deep envy of Ed Balls, one of this year’s contestants. “You’ll want to stop following me on Twitter once Strictly starts.” But that’s for the distant future, when – if – she’s defenestrated. “People keep asking me: do I want to go to Westminster? As if to say: why on earth would you want to stay in your home?” So what, then, if not Westminster? At which point, it dawns on me. Does she want to be Scotland’s first minister?

“Yes. Isn’t that outlandish?” Actually, it is. “I’m not saying it will happen in five years. But I have more MSPs sitting behind me now [she has 31 to the SNP’s 63, and Scottish Labour’s 23] than the SNP had in 2003 [they then had 27] – and they became the government in 2007.” She meets my eye, and holds it, as if daring me to laugh.

How does she get on with the current first minister? Invited to so many of the same events, they see each other often. “There’s always that opportunity to have a quiet word away from the cameras. I think she is a capable, competent woman who acts on the principles she holds, and who is a better leader than Alex Salmond, and I believe that respect is reciprocated. But we don’t go out for pizza and beer; I’m not round Bute House for tea, and nor do I want to be.”

Does she think women do things differently, or is that a sexist assumption? “I think it would be nice if we got to the point where people stopped noticing and remarking on [the fact that] a woman has got a job. I would like that to be the new normal.”

Women are, she insists, in the main every bit as tough on one another in the chamber as men might be. “But the difference is that we’ve all had to experience things we wished we hadn’t, and there is an invisible line we don’t cross. We self-censure because it would put us all back, it would diminish who we are.” Of course she’s a feminist: “That just means believing that women can do everything men can but backwards in heels with a cherry on top. But I think that’s a generational thing. The women coming out of school right now wouldn’t think for a moment they should be considered differently – and woe betide the first 50-year-old man who puts his hand on them because they’ll get a slap.”

We’ve been talking for a while now, and she’s getting restless, which is, perhaps, why she gives me pretty short shrift when it comes to what she refers to as “my interpretation” of what Andrea Leadsom said about motherhood during her ill-fated campaign for the Tory leadership. Still, it’s odd, given that Leadsom’s comments aren’t, by now, in any doubt, and that she (Davidson) made some pretty funny jokes about Leadsom and her ever-changing CV when she addressed the press gallery at a lobby lunch in early July (“A little-known fact is that I was the original Misha the bear at the 1980 Moscow Olympics, which is the same year that I won Eurovision, which, speaking as a mother, is a hard thing to do,” she said).

Still, she makes a point of telling me that she went the other night to Matt Forde’s fringe show in which the comedian did a good skit on the ways children should inform the decisions of those in office. Is she able just to slip into a fringe venue and quietly have a beer? “I’m not a beer drinker. I’m more of a vodka and Diet Coke person, or a glass of white wine, just for the record. But yes, people are mostly nice.” She will try to see a few more things in the next couple of weeks. “My partner has asked if I want to go and see Panti Bliss, the Irish drag queen on Friday…” Oh, but she must. It’s her duty. “We’ll see if that works,” she says, laughing. And apparently, it did. A few days later, I see a tweet she’s written, referring to Bliss. “Great show,” it said. North of the border, this is the new normal: a Conservative leader who enjoys a Friday night out at a drag show. Lucky Scotland, I say.