At the 2017 Labour Party conference, John McDonnell spoke revealingly about how he had been “war-gaming” the challenges a future socialist Corbyn government would face. “It tries to answer the question about what happens when or if they come for us,” the shadow chancellor told activists at a Momentum fringe event. “What if there’s a run on the pound?”

The group anticipating such fates is Class Wargames, a London-based collective founded in 2007 by Richard Barbrook, a 62-year-old academic. Inspired by French Situationist leader Guy Debord, Barbrook resurrected The Game of War (1987), Debord’s book and military board game.

“The Situationists were beaten by a general [Charles de Gaulle] in May 1968, so they thought ‘we’ll train the left to think strategically and tactically,’” Barbrook explained when we met recently at a café in central London.

Players of Debord’s Game of War use a chess-style board “to block their opponents’ lines of communication while preserving their own” and “turn their strategic vision into tactical superiority”. Barbrook, a social sciences lecturer at the University of Westminster, exported the game to Brazil and Russia, where it was played by street-art group Voina (from which the band and protest group Pussy Riot emerged). At this year’s Labour conference in Liverpool it will feature at Momentum’s The World Transformed festival, where Barbrook hopes McDonnell will play.

“It’s hard enough to start a revolution… But it’s only afterwards, once we’ve won, that the real difficulties begin,” Barbrook observed, recalling the 1966 film The Battle of Algiers. “The Treasury and the civil service are definitely war-gaming what happens when there’s a Corbyn government.”

What challenges, then, would a Corbyn Labour administration face? Could there be a “run on the pound?” “I think by the time the Tories have finished with the economy we’re more likely to have money coming back in and the pound going up in value,” Barbrook quipped. But when I cited the precedent of French president François Mitterrand, whose socialist government was forced to retreat by the markets in 1983, Barbrook warned: “We’ve got to make links across the whole of the EU with the rest of the left, I don’t think you can have socialism in one country.”

Barbrook also wants to help address divisions within the Labour Party. He praised A Very British Coup, a live action “megagame” named after the 1982 novel by former Labour MP Chris Mullin, in which a radical left-wing prime minister, Harry Perkins, is deposed by the UK-US establishment. In the game, created by Jim Willman, players join a Labour faction – the “hard left”, the “soft left”, the “old right” – and are forced to collaborate as the “deep state” seeks to overthrow the government.

“The good thing is to get right-wingers to play the hard left and the hard left to play the right-wingers,” Barbrook said. “One of our objectives was to balance the budget – you remember in A Very British Coup they had to go and borrow money off the Russians – and the hard left wanted to abolish nuclear weapons. So we came to a deal where we balanced the budget by abolishing nukes.”

For Labour’s 2017 election campaign, Barbrook developed Corbyn Run, a video game in which players seek to avoid Conservative ministers as well as seize money from tax-evading bankers. “It was the most successful thing I’ve ever done,” he told me.

Born in Nottingham in 1956, Barbrook grew up in Canterbury (his father taught US politics at the university). After joining Labour in 1980 he aligned himself with the Bennite left and has known Corbyn and McDonnell for decades. “John had been in Militant [the Trotskyist group]. He once told me that he was walking round Hayes council estates with another Militant member, who was acting like a feudal land baron, and it was then that he became disillusioned with the top-down, vanguardist approach.” Corbyn, meanwhile, was invariably late for meetings because he’d committed to being present at so many.

In alliance with the Greater London Council, of which McDonnell was finance chair from 1981-86, Barbrook founded Spectrum Radio to “enable refugee and immigrant groups to make programmes for their own communities”. It was, Barbrook said, an early attempt to “circumvent” the mainstream media. “We were trying to do it with analogue radio, now you can do it with digital networks.”

Though he is a tech enthusiast, Barbrook was one of the earliest critics of Silicon Valley’s free market utopianism. In his 1995 essay “The Californian Ideology”, he dismissed tech firms’ hippie image as a facade for “dotcom neoliberalism” and raw capitalism. Barbrook later co-authored Labour’s Digital Democracy Manifesto (2016), which proposed co-operative ownership of digital platforms, a digital citizen passport and universal high-speed broadband.

He is now writing a book about digital rights, as well as one on what Labour can learn from Machiavelli. “I told John [McDonnell] and he said, ‘He’s a good republican.’”

What does Barbrook regard as the greatest danger confronting Labour? “That they just carry on administering neoliberalism,” he said. A chaotic scenario was more likely under the Brexit-riven Conservatives: “Labour will become the party of stability. We’re not the crazed ideologues, which is rather hilarious, we’re the ones who believe in pragmatism.”