One day in March an entire country decided to outlaw all zero-hours contracts. No ifs, no buts, no opt-outs. Yes, I’m talking about the same kind of zero-hours contracts that Sports Direct – which today agreed to pay more than 1,000 illegally underpaid workers around £1m in backpay – inflicts on about 90% of its staff. The deal that means your boss or agency can offer you however many hours whenever they like. The same arrangement on which a million Britons have to manage a weekly shop, the rent and a family.

And no, the zero-hours ban wasn’t brought in by a nation that was famed for its progressive liberalism. The ban happened in New Zealand, which politically and economically is a kind of mini-Britain. We had Thatcherism; they had Rogernomics and Ruthanasia. In the Kiwi battle for fairer work nothing was predictable, and everything was up for grabs.

Two years ago hardly anyone in New Zealand knew what zero hours were. The battle was led by a trade union that just a few years ago had a mere 100 members – and on this issue never expected half of what it ended up with – and relied on the bravery and organisation of a group of workers who are usually waved away as the most lumpen of the proletariat: the staff of McDonald’s, Burger King and the rest of New Zealand’s fast-food outlets.

A few weeks ago I met three of the people in this fight, who told me how they’d pulled off such a coup. I think their story is worth reading now for two main reasons.

First and most vital is that British workplaces are now battlefields in a way they haven’t been since Tony Blair went into Downing Street. Just look at the last few days’ headlines: as well as those Sports Direct workers winning backpay, Deliveroo drivers have besieged the firm’s HQ over a change in their pay, and stretches of Britain’s train network have been shut down by strikes. And add to that the revelations about working conditions for Hermes delivery drivers; the increasingly successful battle of cycle couriers for better pay and conditions; and the first junior doctors’ strike in 40 years. Many of these workers are from companies in the “new economy”: casualised, insecure and un-unionised.

This new fractiousness around work looks set to continue, for one reason: as even the most plodding of economists and politicians are recognising, the old rule that work always pays no longer applies. Workers are still bumping around the same pay rates as they were before the 2008 crash; as the Institute for Fiscal Studies and others show, working middle-income families are the new poor.

More unhappily, all these labour struggles are taking place outside Westminster – because mainstream politicians, Labour and Tory, are desperately trying to keep their party coalitions from disintegrating. While Jeremy Corbyn has referred to the Kiwi battle against zero hours, I can’t see his party getting itself together to do anything about them.

So if you want to see how a social crisis can lead to serious political action, I’d urge you to look a long way south. The story in New Zealand begins with a trade union called Unite. Unlike the behemoth over here run by Len McCluskey, just over a decade ago its Kiwi namesake was “a union without any members”, as Mike Treen, now its deputy head, remembers.

As even the most plodding economists and politicians recognise, the old rule that work always pays no longer works

That changed in two stages. First, from 2005 Treen and his colleagues went all out to recruit workers from the industries other unions weren’t touching: takeaway chains, casinos, hotels. They did so with imaginative, demotic activism. The campaign to get union representation in the fast-food industry was called, with a wink to a Morgan Spurlock film, Supersizemypay.

Its highpoint came with a mass picket of burger restaurants led not by union grizzlies, but schoolkids in uniform. After all, they ate there – so why not form an alliance between customers and workers? Telegenic unrest made for excellent union marketing.

Second came the battle over zero-hours contracts. Two years ago, Treen recalls, this was a term known only by the country’s well-read – and they used it to refer to the parlous labour practices of the foggy old mother country, without recognising how widespread it was at home.

Even after years at McDonald’s, Victoria Hopgood had no idea her contract – requiring her to be employed but not promising her any work – was not the norm, but a new and pernicious thing. Once she got that, and heard there was a union campaigning against it, she dived in.

Crucial to this battle was the teatime TV show Campbell Live. Imagine liberal uncle Jon Snow crossed with the accessible campaigning zeal of Esther Rantzen and you’re most of the way to the presenter John Campbell. In 2015 his team was facing the axe – and yet it still took up the issue of employment contracts as a campaign, appointing a correspondent to work on it full time, the show doing stunts on a nightly basis. Campbell recalls: “The kind of people who were driving Audis to dinner parties to drink pinot noir were decrying zero hours around their dinner tables.”

Treen and his colleagues had one major problem remaining: they still couldn’t get enough workers into their union. Another McDonald’s worker, Alistair Reith, says: “I was born in 1991 – among my mates I was the oddball who’d heard of trade unions.” Chatting to a colleague on the drive-thru, he asked: “Are you in the union?” She replied: “Oh, no. I play rugby league.”

In an industry marked by a high number of Indian-origin workers, Unite did something else unusual: it asked Indian community groups to help with mobilising. Few had heard of the Bhagat Singh society, for instance, but it was large and active – and took its ideal from the eponymous revolutionary socialist who was executed by the British Raj.

Not everything in this story can be readily applied to Britain. Unlike New Zealand, we don’t offer our unions access to workplaces so they can inform non-members of their rights. I can’t see either Channel 4 News, or our equivalent of the rightwing parties that in New Zealand actually drafted the ban, playing the kind of role they did there.

But it does go to show what imaginative activists can do when they move into areas of life that strike the institutional dinosaurs as being a bit too much like hard work.