WE are drinking tea in the lounge of a private club in Glasgow's west end, and Laurie Sansom is poised like a wound up spring.

We've only just met and already there's an elephant in the room. Even before he arrived in Scotland to take over the National Theatre of Scotland from its founding director Vicky Featherstone in 2013, Sansom been warned that he'd ignore native talent at his peril, and that the artistic community he was about to encounter wouldn't tolerate "the imposition of another British arts leader in Scotland" who wasn't ready to "divert the cultural vision away from the historical hegemony of British cultural policy in and for Scotland".

Kent-born Sansom, whose second season is about to begin, must also have read Elaine C Smith's lament for the working-class voice in theatre and television in this very newspaper just last month, following the shadow culture minister's complaint that the arts were too dominated by people from privileged backgrounds.

So, since his venue of choice is the Arlington Baths - founded in 1870 as a members-only organisation for the affluent middle classes - and given that the new NTS season's theme is Belong, I take the plunge. "Are you a posh boy?"

He dives in with disarming vigour. "Not at all. I attended Mascalls Comprehensive in Kent. My dad was a quantity surveyor who retrained as a clown, and my mum works for a tourist information centre. We are a lower middle-class family and I was the first to go to university. I had to do it on my own merit."

Nevertheless, the university he attended was Cambridge, home of the famous Footlights, and he speaks with the fluency, intensity and articulacy characteristic of those comfortably immersed in the world of the performing arts. His forward-leaning body language - legs crossed, hands reaching out, good eye contact - indicates a desire to engage and explain. The fire in his belly, I am about to learn, has been ignited less by Cambridge than by Sansom's experience of Scotland, its people and its indigenous artistic community; in less than two years it has coloured his artistic, and even his political, thinking.

The National Theatre of Scotland's formidable remit is to make theatre for everyone in the country, break down the boundaries of conventional performance spaces, and give writers and actors the tools they need to take their stories to the people. Sansom's job as he describes it is to strike the balance between making work that attracts large-scale audiences like those who attended Still Game at the Glasgow Hydro, and staging the more esoteric works that develop theatre as an art form, develop artists' skills and visions, and encourage new talent. He addresses this remit with new season productions Yer Granny, a populist comedy set in the Minerva Fish Bar and based on the Argentinian play La Nona; a Gaelic version of Whisky Galore touring village halls; Rites, a play about female genital mutilation touring to Glasgow and Manchester; three new lunchtime plays from Ukraine and Russia for A Play, A Pie And A Pint; and a new production of Muriel Spark's The Driver's Seat.

All this is conjured, by necessity, through collaboration, as the NTS is a theatre company without walls.

As we sip tea and admire the Arlington's faded glory I'm suddenly aware of a clever sleight of hand: though the oldest surviving Victorian bathing complex in the world, the club is not as grandiose as it may appear: it's now community-owned, run on a not-for-profit basis, and open to people from all walks of life for a variety of purposes. Sansom loves it; it's handy for the short commute (on foot) between home and work - though he confesses with a rather infectious giggle that he doesn't swim, preferring morning sessions with his personal trainer for weights and bodybuilding.

Now 42, he learned the transformative power of tricks and magic from his father, a children's entertainer who goes by the name of Johnjo the Clown. A new father himself - Sansom was in Hackney, London, to celebrate his daughter Erin's first birthday the day before we meet - he too has the ability to confound and amaze, with a likeable lack of ego.

"I thought you were gay," I say.

"I am," he replies. "My friend from university, Justine, and her partner asked me if I wanted to be a dad. We decided to do it before I was offered the job here. They are the legal guardians and I'm the involved dad. It means I'm up and down [to London] whenever I can be."

His sister is also gay, living in Sydney, Australia, with her girlfriend and twin boys. "I think my parents thought it would be the straight one [his brother] who would have children, but so far he's showing no signs. They joke that it's not how they expected to be grandparents, but they are delighted. Thank goodness society's attitude to sexuality has changed in our time. I used to feel like an outsider, that I didn't belong."

After a string of jobs in regional English theatres - director of the Royal and Derngate Theatre, Northampton, for seven years, preceded by four years at Alan Ayckbourn's Stephen Joseph Theatre in Scarborough - he is well used to the nomadic lifestyle and questioning the notions of belonging and identity - touchstones of the new NTS season, in which families fight for survival, national loyalties are challenged, communities come under pressure, and individuals escape and invent new identities. "You choose your family more now than in the past. People in theatre are always itinerant, part of a big family that shifts and changes. You make long and short term relationships; it's a very particular world to live in."

Currently single, he feels he has settled well in Glasgow, where the NTS offices are based. So settled, in fact, that he's looking to buy a flat.

Sansom read English at Jesus College and his contemporaries included Rupert Gould, David Mitchell, Robert Webb, Sascha Baren Cohen and flatmate Olivia Coleman. Did he feel he belonged there?

"Jesus was mostly rugger buggers and boating and I didn't feel part of that scene at all; all those formal gowns at dinner. But doing English means you end up knowing people at different colleges across the city. Lots of people go to Cambridge to get involved in making theatre. I only had an hour of English a week; you can spend so much time directing and acting. The courses are very well funded, so you can put on productions, which is a big luxury. The infrastructure and money is there."

So is he posh, then? "How do you quantify that?" he asks. "I went to Cambridge and of course I'm part of that now, but I had to make and take opportunities while there. I do think it encourages discrimination, in that that kind of study directs people to vocational jobs. Families need to support that, so it works against the people whose families can't afford to do so.

"When I first came out of university I was able to sign on while finding jobs and auditioning in the theatre world. That's not possible now, which is a pity, because it's a good route to being accepted by that community.

"The real issue is about opportunities in the arts being equally open to other ethnic and social groups. It's not a false debate; it's one we should be having."

He points out that in regional hubs like Watford and Birmingham, this is not the case and that there is "extraordinary" work going on in different ethnic and social groups which attracts a broad section of people who don't naturally buy theatre tickets.

I ask him to define what being Scottish means, and what - if anything - he thinks makes the country different from the rest of Britain. "There are so many facets to communities in Scotland it's wrong to make sweeping generalisations, and post-Referendum, it's got more complex," he begins. Glasgow for example has "many, many audiences" that include new migrants, native Gaelic speakers, disabled and the poor, and he knows he needs to address them all.

He admits he was never taught Scottish poetry or literature at school, and at Cambridge only in relation to Chaucer. "The fact that Henryson, Hogg and Smollett were Scottish was not made out to be important, and we weren't directed to read them. I did a whole dissertation on Smollett without realising he was Scottish.

"But I was never taught any Scottish history ever."

How did that affect him when he arrived in Scotland to direct the James trilogy, written by Rona Munro and performed at the Edinburgh Festival in the weeks before the Referendum on Scottish independence? The three new plays, about Scotland's least-known medieval kings James I, II and II, were a co-production with the National Theatre of Great Britain and played London in September and October. They were the flagship productions of Sansom's first year of programming.

"It made me really curious and it excited me. It made me realise there was a whole history of a country out there to be explored. The James Plays allowed part of Scottish history to be re-owned. I think the story of how Scotland became a nation is really interesting, how for a long time it was run by different families. I didn't know about that; it asked the question of how we tell Scotland's relationship with Scotland through English history."

Did they influence how people voted in the Referendum? They certainly divided audiences. "There was a high level of engagement with this cycle and what it said. What it said politically was quite slippery," he says. "How plays and theatre influence people's ideas is difficult; you're never in control of what other people think of them and that's as it should be. People's response says more about them.

"It made people think about the Referendum; I don't know anybody who changed their mind about it. I hope they formed a part of the debate and part of the thinking.

"But always I wanted the plays to be part of the nation's confidence, whatever the result. I hope they showed people that actually we could be on the world stage, that the National Theatre of Scotland can hold its own against the National Theatre of Great Britain.

"I want the artistic community in Scotland to feel confident and ambitious enough about their country to make work that's both magical, complex and also about Scotland today."

How did he vote? "I'm not going to say. Before I came to Scotland I don't know how I would have voted. Being here and being part of that extraordinary year did certainly influence how I felt."

He enthuses about finding buried stories. "As a theatre maker you want to find the surprising, exciting challenging stories; that's the job. That's when you realise there are gaps in your knowledge. One example is Glasgow's place in the Empire, the sugar, tobacco, slave trades, which Louise Welsh explored so well with her Empire Cafe during the Commonwealth Games."

He acknowledges that while England knows its history through the plays of Shakespeare, Scotland lacks a similar "canon" of historical work due to the prohibitions of 16th-century Scotland's Calvinist Reformation. "There's no equal to Shakespeare in Scotland, and a pre-19th century 'canon' doesn't exist, with David Lyndsay's A Satire Of The Three Estates the notable exception. If you don't have that canon, you wonder, is the country able to stay in touch with that part of its history? That's why it's a great provocation for people like Rona [Munro] and for David [Greig], whose Dunsinane, an irreverent sequel to Shakespeare's Macbeth, tours the US this spring. The lack of a 'canon' makes it attractive to look to other cultures.

"But we do have a rich heritage of Scottish pantomime and variety, and an extraordinary number of 20th-century plays. I hope we can revive some of that post-Second World War work in Scotland, such as [John] McGrath, Jo Clifford, Bill Brydon and so on."

The NTS is directly funded by the Scottish Government and one of the things it wants from it is to take theatre to other places. It has been in the US, Canada, Beijing, Australasia. "Those international collaborations have to feed back to the life of artists in Scotland, to allow us to make a difference to our culture. So rather than import work from other places, we make something brand new and share it with other cultures."

Does he feel Scotland is parochial? His answer is swift and unequivocal. "Scotland has a more international perspective than England in my experience. That sucking of the energy of London ... it doesn't have to look outside itself. Scotland has always looked beyond the North Sea to the USA, made new connections with other nations, yet its global influence is under-represented. London doesn't see that part of Scotland.

"London only started to look at Scotland two weeks before the Referendum vote last September, and only when it was nearly a Yes. Suddenly they had to be interested. Well, you haven't been interested enough, have you?"

So it's London that's parochial? "It seems counter-intuitive to say that, but yes."

He name-checks last season's Scottish Enlightenment Project, a collaboration with the NTS and the US company The Team, which looked at how the Scottish Enlightenment built the US free market.

"I didn't know that before I came up here. That is something which surprised me. Scotland defining itself against the larger power makes it look for interesting productive relationships outside of itself. That's really healthy and I want to harness that."

He's full of praise for the "extraordinary acting talent in Scotland", saying Jack Louden and James McArdle will become international stars.

Is there a question around recruitment of Scottish leaders of cultural institutions? Vicky Featherstone - a much more vocal leader than Sansom - claimed she was the victim of anti-English bullying during her tenure. "She took a lot of the heat. I've felt very welcomed in Glasgow and I like that you have to prove yourself. I want to do my five years. I want to make sure that whenever I leave there's a wealth of Scots and Scottish-based candidates with others in contention for my job."

So is Scotland about to have its moment? "Scotland's journey is just beginning. Oh God, it is."

The National Theatre of Scotland new Belong season starts tomorrow [Monday March 23, 2015] with A Play, A Pie And A Pint at Oran Mor, Glasgow www.nationaltheatrescotland.com

Meet The Artists ... In Conversation With Laurie Sansom at the Traverse Theatre, Edinburgh, takes place on Tuesday March 31 at 7pm. For the chance to obtain free tickets, join the National Theatre of Scotland mailing list via www.nationaltheatrescotland.com