Exclusive:Irvine Welsh on why his Trainspotting musical is delayed, his final Ray Lennox book and his forthcoming love story

The writer admits he is as impatient as anyone for a new musical adaptation of his best-selling debut novel to make it onto the stage.

It is almost three years since Welsh first announced that he was joining forces with songwriting partner Steve McGuinness and producer Phil McIntyre to create the production.

However Welsh admits their plans to launch the show in London’s West End have been held up by the slow recovery of the theatre industry since the pandemic.

He says: “The show is basically all ready to go. The script and the songs are all done. We’re really just waiting on the right theatre.

“We want to start off in the West End and move it out from there, but we’re very picky about the theatre we want.

"We don’t want to come in too big and not have a full house all the time. But we want it to be a big show, so we don’t want it to be a tiny place or for it to be an afterthought.

We were offered a couple of slots after shows were cancelled to come in for around eight weeks, but we didn’t want to do that.

“I think it’s a really strong show and we want to give it it’s best shot. The producers have been great. They know what they’re doing and have been really patient.

“I’m the most impatient person in the world. I want everything yesterday.

“I’m trying to be a bit more zen about it, but it’s not easy when people come up and ask: ‘What’s happening with the Trainspotting musical? When’s it coming out? It’s getting a bit embarrassing.”Welsh appeared at a number of events last year to mark the 30th anniversary of Trainspotting’s publication and was also the subject of two recent documentaries, while an “immersive” theatre production has been a mainstay at the Fringe since 2017.

Welsh said: “I’m always looking back at Trainspotting. It’s so much part of the culture that people haven’t really let go of it and new generations are discovering it all the time. I’m kind of compelled to talk about it.

“It’s like having a sort of jakey best mate that you want to avoid who then suddenly he gives you a big wad of cash that he’s owed you for ages.

"I’ve really got into Trainspotting again with the musical we’ve been developing.

“In some ways, it’s darker than the book or the film. I think we have to go there. Musicals can be very trite. But you can also get away with a lot of darkness.

“West Side Story and Rent are actually very dark thematically, but are also very optimistic and upbeat.

"The times that we’re living in now are so dark and bleak. We have to provide something upbeat, inspirational and quite joyous, but still hammer home the message.”

Welsh, who launched a new dance music record label two years ago, will be heading in another musical direction to accompany the next book he plans to write.

He said: “I’m writing a book about men in love, a kind of twisted romance, but I want to bring out a twisted disco album at the same time as the book.

"I think there’s a completely psychotic edge to romance. I think you can tell that anybody who writes about love and romance has got to be a nutter. So here I come.”

Welsh, who has lived Edinburgh, London and Miami in recent years, was back in his native city this week to launch the latest novel focusing on troubled Edinburgh detective Ray Lennox – which features a character named after fellow author JK Rowling outbid the outspoken broadcaster Piers Morgan at a charity event.

In Resolution, Lennox has left the police and the city behind for a new life, including a new relationship in Brighton, only for an encounter with a wealthy, smooth-talking businessman to reawaken memories that have haunted him since childhood.

Although the character has been brought to life on screen by Dougray Scott recently, Welsh insists the latest novel, Resolution, will be his last Lennox book.

Welsh, who co-writes the TV scripts for Crime with regular collaborator Dean Cavanagh, says: “I didn’t want to write a franchise or anything like that and I’m not really interested in police procedural stuff. The first book was really an existential thriller. The TV series has been pretty opportunistic.

"I became friends with Dougray years ago and after reading Crime he told me: ‘I’ve got to play this part.’

“We tried to get it made as a movie, then finally got it made as a TV series during lockdown and it really well. The first series was sold internationally and Dougray got an Emmy.

"Everyone seemed to want it and I was asked if I had any more Lennox stories. I’d written a rough draft of this new book as a follow-up to Crime, but then thought there could maybe be a trilogy. I wrote The Long Knives, which became the second series and Resolution will hopefully be a third.

"I actually think the new book is the best of the three. It satisfyingly resolves Lennox’s story of why he is like he is, how he comes to terms with that, and his quest for vengeance.”

Welsh will be discussing Resolution at next month’s Edinburgh International Book Festival, which has been embroiled in controversy over its sponsorship with Baillie Gifford, amid protests over the investment firm's links with the fossil fuel industry.

Welsh said: “Culture has always been under-valued by governments, which in some ways I think is great, but now it’s seen as an industrial concern.

"Public funding has been massively on the side and funding for the arts is so reliant on private money now which has all kind of consequences. In the era we’re living in now, all money is dirty money to some extent.

“I suppose I can afford to have this view as I’ve never been dependent on the public purse, I’ve just sold things, but I kind of think we need a dose of anarchism again.

“I love festivals. I think they’re great to go to hang out and meet people who are into books, films or music, and meeting other people who produce stuff.

"When I started out, we weren’t really that bothered about the book festival, how much the funding the Scottish Arts Council was getting or sponsorships.

"Part of me thinks we should take it back to the grassroots and grow proper culture.”