AS he describes the unfolding narrative of his TV series Crime, two states of mind are going on in writer Irvine Welsh’s feel for it: both a serene strategy, and a wrecker’s glee. He has taken the most popular TV genre, the “pacey, entertaining cop drama” and turned it inside out.

“The biggest point for me” says Welsh, “is that Lennox (the hero) is NOT a cop. I’m not really interested in someone who is a servant of the state in that way.”

The plan has always been to use the crime genre as a “Trojan horse” to capture the audience, and then to turn it into something else: “an existential thriller,” the story of a man “trying to solve the mystery of himself.”

Conventionally, the cop is the good guy whose role is to make sure the bourgeoisie can sleep soundly at night. To protect property and put the bad guys away. But Lennox is different. He does it for other reasons.

In Series 1 his own brother calls him a class traitor, hired to lock up the working class from which he came. So who is he, and why does he do it?

“He’s this avenging angel,” says Welsh, “using the power of the state to meet his own needs.” At first we meet a policeman whose buried motivation for doing the job is somehow “cathartic for his own abuse.”

And Season 2 is “a massive leap forward” because Lennox becomes aware that the state is using both him and the wider police force to protect itself. “For the entitled,” says Welsh, “to abuse is their privilege. It’s their prize for winning the class war.”

You can feel the political self-education that lies at the foundation of his work. Where did that come from?

A fundamental experience was to work with the screen-writer Jimmy McGovern on Dockers in the late 1990s. While the strike in Liverpool was still going on they made workshops with the strikers themselves and “it was such an education,” he says.

The situation that the work describes always the same — it’s the way the class is divided against itself — but the question is how to make significant drama from it.

“These guys had been on picket lines for a year and obviously they hated the scabs, their ex-workmates and comrades,”says Welsh. “And Jimmy said: you’ve got to love the scabs.” The strikers were appalled — it was tantamount to blasphemy, but McGovern insisted and “it was such a ballsy thing to say to those guys.”

You can feel the power of the confrontation between dramatist and strikers even now, 25 years later, and it revealed a fundamental truth: “It won’t work as a drama unless you love the scabs because the strikers won’t come alive unless the scab is a real character.”

In other words, when the class is divided and you want to show the reasons why, you can take sides for sure, but you must empathise with everybody. Only then can the conflict become clear, and only then can the social context reveal itself.

This experience helped Welsh to develop his own strategy, and his own way of speaking to working-class audiences.

“If you think about the whole post-war, welfare state, social democratic Britain — everything was documentary, kitchen-sink drama where you show people in poverty and distress,” he says. Artistically, “it was almost an advocacy role. You’re advocating that resources go to sort out these social problems.” But come 1984 and Orgreave, “that was the end. The class war was won by the ruling classes. Labour was crushed. Capital was ascendant. So all you’re doing now when you show poverty is saying ‘it’s great being rich and shit being poor’. It’s become like a pornographic thing.”

Ken Loach’s film I, Daniel Blake, for example, was described — accurately — in the Times as “poverty porn.”

“So,” he continues, “how do you get back to that level of conflict?”

To show class conflict, rather than class victimhood is the nub of the matter. And for Welsh right now the answer is “to show the state in how it operates, and how it expects its servants to operate.”

Certainly, this is the strategy for Season 2 of Crime. Lennox finds the strain of being in that role unbearable and he confronts it directly.

“So, he has this incredible, never seen before on TV, this brilliant speech where he sits down at a promotion board, all career cops and councillors and officials from the Scottish Office, and tells them why he doesn’t want the job.

“I’m so proud of that, of the whole season, and I’m absolutely bursting with anticipation to see how people are gonna react to this.”

And then: “Fair play to ITV for letting us do it.”

To have earned the platform, to have won the awards and attracted the mass audience is a delicious success, and moving from ITVX to ITV they got double the projected audience. But it is difficult to create a space that can react against the neoliberal conservatism of the media. “You have to treasure it,” he says. “You have to be careful. You can’t be preachy, because if you do that then people will shut off. These truths have to be told dramatically for people to relate to it.”

This is an existential thriller, masked as a cop show, but does Lennox’s awareness become class conscious rather than merely subjective?

“That’s basically season 2,” says Welsh. But he sees that path to that consciousness entirely through the prism of his characters: “His counterpoint Drummond says ‘we have a job to do, to put bad people away’ and he’s like: ‘Can’t do it’. Because it comes with so much else. And she’s like ‘Ignore the so much else and focus on this...’ They have this debate. And you want people at home to have that debate. You want that pushed to the forefront of things.”

Will season 3 be a cop show without a cop?

“Yes. Exactly. That’s what happens,” he says. “The book’s coming out in July and hopefully it will be based on that. It’s called Resolution and in it he becomes... an enemy of the state. Pursued by the police. You could even say he was a terrorist. That’s the logical conclusion.”

Is this an act of wish fulfillment? Is he giving false hope that the good guys will come through?

“The answer is yes,” says Welsh. “And you have to. The whole spirit of resistance and social change hinges on the notion that there can be such victories. You have to show what that’s like and show the satisfaction in that. Because if you don’t, there’s no... no goal that’s visible. There’s no motivation.

“And what you do is to work through your own uncertainty. To figure it out as you go along. And for that — you have to let the subconscious do the heavy lifting!”

Crime series 2 is released on ITVX and STV on September 21.