'With each novel I dare myself to try something risky, asking – have you got the guts? And somehow I’ve got away with it.'

Dirty Dick’s isn’t a pub that Warner was ever in the habit of frequenting. Rather, he just liked the name. It “suited the novel”, The Sopranos, he says. It was in pubs like these that he wanted to place his vulgar, sex-crazed, booze-enhanced schoolgirls from his fictional “the Port” on their messy, emotional daytrip to Edinburgh for a singing competition. Nor is this exactly the kind of place he went himself as a teenager to escape the town of his own childhood, Oban, upon which “the Port” is based. He and his teenage friends would head down to Glasgow, not Edinburgh, on the train, catching the 1am back home to Oban, usually after a night at some gig. “Anything that was on at the Apollo: Rory Gallagher, Clapton, Hawkwind, Captain Beefheart. I hung out with the heavy metal crew.”

Today is neither a sambuca nor a nine-pint day, as we sit down for a relaxed chat in the pub about, among other things, Our Ladies Of Perpetual Succour, the National Theatre of Scotland’s musical theatre show based on The Sopranos. Seventeen years later, the show, with its the all-female cast, angelic choral moments, Electric Light Orchestra numbers and potty-mouthed swearing and anecdotery, took the Fringe by five-star storm last year, and is touring the UK.

Warner pulls a scrap of paper from his pocket: a limp page ripped out of a Spanish book (he has a house in Spain, where he goes to write). On the back is scrawled a list of dates for the show. “You have to see it,” he raves, as if really it had nothing to do with him. “It’s fantastic.”

On one level, the 52-year-old sees Our Ladies Of Perpetual Succour as “ancient history”. The Sopranos was his third book, published three years after his debut, Morvern Callar, made him one of the hottest voices in fiction. But it’s also very “now”. It is what happens when a book takes on a life of its own – in this case, when playwright and screenwriter Lee (Billy Elliot) Hall and the National Theatre of Scotland nurture your book and give it a rebirth.

Last summer, Warner wasn’t really thinking about the musical that was being staged of his book. His father-in-law, who also lived in Spain, was dying and ultimately passed away in July. “It was an awful time,” he recalls. On one occasion Warner came over to Edinburgh on business and realised that the play was on. He didn’t want to go to the first night. “People will look at me and stuff,” he thought. “And they’ll all ask, ‘Did you like it?’”

Eventually, Lee Hall persuaded him to attend the third night. “I was sitting next to Lee and could tell he was nervous as well. But within 10 minutes I just loved it. I wasn’t the author any more. I was just a punter watching a great show.” It is, he sums up, “Grease meets a female Trainspotting”.

Vicky Featherstone, who directed the show, described it as “a lament for the power of youth, and how you’ll never be that fearless again”.

Warner has written eight novels, but two stand out as having brought him the most success and recognition. One was The Sopranos, whose movie rights sold for £500,000, though the film was was never made, and whose characters returned for a second novel, The Stars In The Bright Sky. The other was Movern Callar, republished last year as a Penguin Vintage Classic, and adapted in 2002 into a mesmerising, critically-acclaimed film by Lynne Ramsay. “It’s strange,” Warner says of the way these books “keep knocking around”. “Even a doubting Thomas like me, starts to think maybe there’s something in this. Maybe it’s not just blind luck of the industry, maybe people really are seeing something in these books.”

Morvern Callar played its part in a significant renaissance moment in Scottish writing. James Kelman had won the Booker prize, Jeff Torrington, the Whitbread; Trainspotting had been published to huge acclaim. “It was one of those lucky cultural things,” says Warner, “like punk rock or jazz. It was an interesting time in Scottish culture. The media added to it. And sometimes there’s a truth in the hype. Sometimes it obscures certain truths. A similar thing happened in Prague in the 1980s. Incredible writers, the media got very excited.”

It was, he says, like being at the “centre of a hurricane at that time”. He, Irvine Welsh, Gordon Legge, Paul Reekie and others were dubbed “the Beats of Edinburgh”. A journalist came over from the New York Times and persuaded them all to gather in a pub, which they agreed to, provided she paid the bar bill.

Warner compares this experience with that of his former school-teacher, the celebrated poet and novelist Iain Crichton Smith, who never was wealthy enough to support himself to write full time until he had retired. “He was a guy from Oban too but the New York Times didn’t come to interview him. So as a writer if you’re honest with yourself you both go, ‘Wow this is a stroke of luck’, and you also go, ‘I would be an asshole not to go with this’.”

One of the factors, Warner considers, was that this was boom-time 1990s, and, in the publishing industry, a time of big advances. “In a weird way,” he recalls, “large advances became part of the promotional budget for the book.

“There was a lot of money flying around. It was possibly a decadent time in our society. A lot of free credit about. Property prices were rocketing. It was a fast-moving society. And I also wonder if part of that is related in a way to what I was writing about in The Sopranos. Young girls suddenly with a little more money in their pockets who can afford to go around the bars and drink.”

For a writer, Warner has certainly seen relatively big money in his time. And he has done his partying: “I’ve got excited a few times,” he confesses. “Fallen around in bars and hotels.” But for the most part, he has been moderately careful with his money. “It’s not easy to survive as a writer,” he says. “You need to be wily. There’s a bit of a gamble to it all.”

Currently Warner teaches creative writing at Edinburgh University. His main message to his students is simply to read: “You become a writer because you grow through the books you read.” Famously, Warner read very little until age 15, when it became an obsession overnight. The story goes that he picked up copies of The Graduate (Charles Webb), The Outsider (Albert Camus) and The Immoralist (Andre Gide) because their cover-images suggested some kind of sexual content, and was hooked.

He remains alive to the struggle it is for other writers, particularly the young, to keep writing and get published. Partly, he blames the arts funding body Creative Scotland, of which he is highly critical. He praises an article by Sunday Herald theatre critic Mark Brown, which described the public body as built around a “philistine, market-driven ideology”. “A horrible disconnect,” says Warner, “has occurred between the artists and the Government’s representation of the funding in Scotland. The artists and writers feel completely alienated from a very well-financed organisation that doesn’t seem to actually be related to them in any sense. It just seems to be doing its own thing. They’re fulfilling functions without any real relations to the artists around them.”

He has not applied for Creative Scotland funding, but says: “I am disgruntled and upset by the situation they have created through lack of communication.”

It’s time for the organisation “to start mending fences” he suggests – and jokingly proposes himself as mediator. “Perhaps I can be the Acas, Alan Warner Conciliation And Advisory Service. And forgiveness can take place. Because it needs to. Because a lot of writers are struggling to get their work out there, get it published, and then after it’s published, get some sort of sense of continuity.”

Currently he is working on two books: Marco Sent Me North, about a rock star’s assistant who is sent up to a house on Scotland’s west coast to dislodge some tenants, and Oh Boys Of The West Slow Down, a romance set during the run-up to the Scottish independence referendum. “Mills & Boon with whisky,” is how he describes it, adding that the narrative will also examine, “the caveman stuff going on in the minds of Yes and No voters”.

As a Yes voter, he enthuses about how far Scotland has come along the road to independence. “In 1995 I was in Hungary with Don Paterson and Kathleen Jamie and we had a debate about this on the train. I remember saying, ‘Kathleen it’s impossible. It won’t be allowed to happen. Big business won’t allow it to happen.’ And I was proved both right and wrong. The system did fight it. But we came so close.”

Warner and his half-Irish, half-Spanish wife, Hollie, have no children. “I think we’ve left it a bit late,” he says. Despite his success, the writer’s life is an insecure one. “I’m addicted selfishly to doing this thing I do, which is massively time-consuming. You know, two years to write a book, if not longer. But kids ground you in lots of ways. It would be nice.”

While he lives mostly, currently, in Edinburgh, Spain is where he goes to “hide” and write. “When I’m there I’m not hanging out with bearded poets drinking red wine, discussing Lorca. It’s not like that. I’m more likely to be in the Benidorm Brits bar with Union Jacks. Of course, I have Spanish friends but they’re not writers.”

One of the things he treasures about his time there is the anonymity. “Friends there know I’m a writer but they don’t really take an interest. There are lots of ex pats, retired, just knocking around the bars, living the good life. I just fit in with that. No-one’s interested in what you do. They just assume you’re on holiday, or retired, or you’ve had a lucky break on the horses.”

Nevertheless he has not entirely disconnected from “the Port” of his childhood. For a long while he and his wife had a house up there, though they have now sold it. His parents have both passed away, his father in 1996, his mother in 2000. The Marine Hotel, where he grew up and which his parents ran, is still there on the front, now called the Regent. “It was an amazing place to grow up,” he recalls. “We had a penthouse at the top of the hotel. The view of Kerrera and Mull beyond, the mountains which in winter would be covered with snow.”

Warner’s only sibling, a sister, was 13 years older than him, so for the most part he felt like an only child. It was, he says, “a deliriously happy childhood and upbringing”. Not for him the cliché of the writer forged out of suffering. Beckett, he observes, said the same thing. “He said contrary to speculation he was not beaten by his father. He said he had a very happy childhood.”

The Sopranos follows the pupils from an all-girl Catholic school called Our Lady Of Perpetual Succour. Such a school did not exist in Oban, though there was, it turns out, a very small co-educational Catholic school there when Warner was a boy, which became amalgamated into the local high school as he was growing up. But it was not this school which inspired Warner, but rather the tales his wife, Hollie, would regale him with, of her state convent school days in Ireland. “I remember thinking, wow this is a complete culture. What if I took that concept and just moved it onto the west coast? Anybody going to notice?”

Often it seems, in his novels, that Warner likes to take a risk and corner himself inside the constraints of a format or idea. In the follow-up to The Sopranos, The Stars In The Bright Sky, he traps his girls from the Port in Gatwick Airport for days, the premise being that they have planned to book a last-minute holiday, but never quite manage to achieve this. “There’s a great jazz musician called Wayne Shorter,” he says, “and he was asked by a journalist what’s your definition of jazz. Shorter said, ‘My definition of jazz is: I dare you.’ No reference to music whatsoever. I was always struck by that. I try to keep that with each novel. I dare you. Have you got the guts? Try something risky.”

Even now, he seems to marvel at the fact that he has managed to make a living this way. “I can’t believe that for 20 years, I’ve been able to write exactly what I want to write with no outside interference,” he says. “And somehow I’ve got away with it.”

“Blackjack,” he calls the process of writing. “It’s like every book is another hand on the card table.”

Luck, it seems, is currently with him. With Our Ladies Of Perpetual Succour it’s as if, without even drawing a fresh card, he has managed to score 21 again.

Our Ladies Of Perpetual Succour opens at the Dundee Rep Theatre on Thursday and is touring venues around the United Kingdom until October 1 www.nationaltheatrescotland.com