After a long, hot summer of screaming angrily into its own navel, the Labour party is finally talking to the outside world again. Or at any rate that’s one way to look at John McDonnell’s plan to curb the gig economy, unveiled at the TUC conference. The shadow chancellor thinks there’s every chance of a general election before too long, given the parlous state of Brexit negotiations. So while Jeremy Corbyn spent the summer alternately mobilising the faithful at rallies and going round in circles over antisemitism, McDonnell was returning to the roots of what made the movement so popular in the first place: radical, sweeping, anti-establishment ideas on economic inequality.

At the weekend, he proposed making larger companies split their profits with workers via share funds. Now he’s promising that under Labour all workers, including agency staff, would be entitled to rights such as sick pay and maternity pay from day one, while working relationships would be redefined in law to stop gig employers dodging their obligations via the sort of weaselly contracts that give self-employment a bad name. Bang goes the platform model pioneered (albeit since modified) by the likes of Uber, offering most of the obligations of a job minus the perks and protections to their drivers. No more zero-hour contracts across industries from pubs and restaurants to social care, either.

It’s classic McDonnell; bold, faintly nostalgic and brooking no exceptions. Never mind the findings of Matthew Taylor’s recent review that many people actively prefer casual work because it fits around family responsibilities or studying, or that this unusually elastic labour market may have helped Britain deliver higher wage growth. It’s all about a return to an era before employment was so routinely casualised and as such it’s likely to be very popular. People just want some security and some basic trade union rights to protect them, McDonnell told Radio 4’s Today programme, and who would disagree? Alarm about the human consequences of insecure working practices is shared on both sides of the warring Labour party. Frank Field, who recently quit to sit as an independent, was a vocal critic of gig employers and McDonnell’s announcement was welcomed by Wes Streeting, who is hardly a Corbyn fan but has plenty of black cab drivers among his Ilford constituents.

But more importantly, it is also widely shared by voters who are increasingly dismayed by stories of callous treatment. It’s not just about money, it’s about feeling like a human being whose welfare actually matters to your boss.

So employers wailing that McDonnell’s proposals will kill off jobs or disadvantage the British economy would do well to reflect on why they have ended up here. Talk to their workforces and it’s clear the real damage is done by combining insecure working practices with an inhumane and rigid management style, which sets ridiculously punishing daily targets while making clear that if you can’t cope then someone else could fill your boots tomorrow.

Court cases brought by unions such as the IWGB (formed specifically to represent gig economy workers) and GMB have repeatedly found them to be on the wrong side of existing law. If employers hadn’t systematically pushed their luck then it wouldn’t have come to this – and while even two or three years ago McDonnell might have been successfully portrayed as a luddite trying to hold back the economic clock, now he’s moving with the mainstream. Under pressure from the unions, the courts and public opinion, gig economy employers are already tweaking their model and even Theresa May is at least theoretically committed to better holiday and sick pay rights for gig workers.

The one nagging question is whether people who actually like freelancing – or at least see economic precariousness as a reasonable trade-off for not being tied down – could become the unwitting casualties of a war that isn’t about them. Self-employed work runs the full gamut now from exploitative and badly paid to liberating and lucrative, and has been a lifeline especially for working parents whose family lives don’t fit neatly into standard office hours. If Taylor is right and the expense of turning casual jobs into something more permanent means fewer jobs in the long run, McDonnell’s strategy risks unleashing some seriously perverse consequences. To make this work in practice, compromises may be necessary.

But if nothing else at least we’re now back to thrashing out the pros and cons of ideas that could potentially change lives, after a summer in which both political parties had begun to seem dangerously detached from many voters’ daily reality. Politics is back, and the relief is palpable. Now let the arguments begin.

• Gaby Hinsliff is a Guardian columnist