When Damian Barr’s memoir Maggie & Me was first published in 2013, it caused an immediate sensation. Here was a brilliantly vivid and completely gripping story of a boy growing up in North Lanarkshire in the 1980s, when Margaret Thatcher’s approach to economic policy was both starving public services of cash, and steadily dismantling the heavy industrial base on which the local communities had been built – even, in the end, closing down the mighty Ravenscraig steel plant where Damian’s dad worked.

Yet young Damian could not bring himself to hate Margaret Thatcher as everyone around him did. Instead, he developed a secret admiration for this glamorous and apparently unstoppable figure, with her blue suits and perfectly-groomed blonde hair; and Maggie & Me is, in a sense, all about the reasons for his refusal to fall into line with the pervasive local opinion of her.

For young Damian, even at seven or eight, was a boy who had already experienced exclusion from his own community on a scale that left him with no sense of obligation to share all of its views – rather the reverse. He was very bright, he was very gay, and in a fiercely sectarian time and place, he had a Catholic mother and a Protestant dad.

Damian Barr and James Ley PIC: Kirsty Anderson

He therefore not only admired Maggie’s glamorous style, but identified strongly with her isolated position as a woman among men, and as a lower middle class girl among those from much more privileged backgrounds; and she became an icon of achievement for him, as he planned his escape from a community where he had been bullied, scapegoated, sexually exploited, and horrifyingly brutalised by his mum’s violent boyfriend. Hence the book, with its stereotype-busting title; and hence, 11 years on, the new stage version of Damian’s story now being produced by the National Theatre of Scotland, in a version scripted by Barr himself and playwright James Ley.

“In the early 80s, Maggie Thatcher was just unavoidable,” says Barr, from the home in Brighton he now shares with his husband and several chickens. “She was everywhere on the news, and even people who hated her talked about her all the time. You had to have an opinion about her; and I think I just felt, as a boy who already knew all about being different, that my opinion wasn’t going to be the same as everyone else’s.

“I do also think that the language of individualism she talked, and of individual striving and achievement regardless of your background, was important to me then. Of course, looking back as an adult, I’m now fully aware of the limits of individualism, and of the pain her policies inflicted on communities and people that I loved. But throughout history – or at least until very recently – gay people have always had to move away and move on, to find a place where they can really be themselves; and for me, in that time and place, she was the one who made me feel I could do it.”

In creating a new stage version of Damian’s story, though, Barr and James Ley – both brilliant gay writers of the same generation – have found that simply adapting the book, as it was published more than a decade ago, is not really an option. “This is going to be a classic piece of modern Scottish storytelling,” says Ley, best known for smash-hit plays including Love Song To Lavender Menace, Wilf, and Ode To Joy. “Two acts, an interval, and a real blend of forms, with songs, a touch of agitprop, magic realism and naturalism – because the quality of Damian’s naturalistic dialogue, both in the book and in the new material he’s written, is wonderful.”

“I’ve been surprised by the process,” adds Damian Barr, “because it really isn’t just dramatising the book. It’s more like deconstructing the story and rebuilding it on the same foundation, but with completely different techniques; and of course doing it ten or 15 years on, with a whole new perspective. So I find that I’m still writing new speeches for the characters even now, because the process is giving me new insights into them.”

Despite the decades that have passed since Barr was growing up in Newarthill, though, his personal story remains an intense and troubling one, involving the breakdown of his parents’ once happy marriage, the shocking homophobic violence of his mother’s new partner, and the culture of silence and harsh social judgment that made it almost impossible for him to tell anyone what was happening.

“It was quite difficult for me, stepping into the rehearsal room for the first time,” says Barr, “because I knew that in a sense I was going to see, and be with, all these people I had loved and lost, coming to life again through theatre. I thought it could be overwhelming. But we have an amazing creative team working on the show – our director Suba Das, musician Susan Bear, designer Kenneth MacLeod, seven great actors – and I have loved working with them to make what’s really a new story, based on the book.

“In the end I think writing anything – a book, a play – is always about letting it go, and allowing the readers or the audience to find its meaning, for themselves. But I do think it’s important that stories of gay lives continue to be told. When I started writing Maggie & Me, almost 15 years ago, I thought we could take it for granted that things would keep on getting better for gay people; but I don’t think that now. Despite all the progress, there’s definitely a backlash of sorts under way; and that only makes it more important to keep on telling these stories – in books, in theatre, wherever we can.”

Maggie & Me is at the Tron, Glasgow, from 7-11 May, then touring to Inverness, Perth, Cumbernauld, Dundee, and Edinburgh until 15 June, see www.nationaltheatrescotland.com

Damian Barr on adapting his memoir Maggie & Me for the stage: ‘I thought it could be overwhelming’