Some defenders of democracy tog themselves up in suits, joust over case law and star on the teatime news. Others raise two boys single-handedly in a market town in Essex, carry a smartphone with a perma-cracked screen, and do their best work in the dead of the night when the kids have gone to bed and there’s finally a bit of peace and quiet. Like Shaunagh Roberts.

Roberts doesn’t hang out in courtrooms and can’t quote Latin, yet her battle shines as bright a light on our corroded politics as any case in the supreme court. I’ve been writing about it in these pages for over a year: how she and an entire community are fighting this government and one of its central dogmas to save their local school. And now we can exclusively reveal that in the past few days, Roberts has forced the education secretary, Gavin Williamson, into a historic climbdown. Her victory is to be celebrated, even while it raises other profound questions about what kind of democracy we live in.

The way in which our school system has been transformed this decade has been a rehearsal for the way in which our democratic norms are now being trashed

Not that Roberts saw herself playing any such role in the spring of 2018 when she and other parents at Waltham Holy Cross primary learned that the school had been judged inadequate by Ofsted inspectors and would be handed over to Net Academies Trust. It was only as Roberts began looking into those put in charge of her sons’ education that she learned that three Net schools had already been given to other trusts: evidence of Net being itself a failing trust.

As she and other parents kept digging, they found that other locally known trusts had been recommended by Waltham Holy Cross but turned down – for no apparent reason. And they began to see the contempt for democracy that runs through the system for forcing “inadequate” locally run schools to convert to academies.

More than 300 other primaries have been given to private trusts under this system in the past three years, yet neither parents nor staff are given any details about why a trust has been picked to run their local school – and this system affords them no say. Public meetings, parents’ marches and days of strikes (unheard of at Waltham Holy Cross, where barely any of the teachers were union members before) made no difference. No one wanted Net, and the transfer date kept getting pushed back, yet still the officials at the council and in Whitehall were adamant: the primary was going to Net.

The way in which our school system has been transformed this decade has been, in its ugliest political facets, a rehearsal for the way in which our democratic norms are now being trashed. With academy schools, as with suspension of parliament, two of the key figures were Michael Gove and Dominic Cummings. In the face of widespread protest, Gove used procedures meant for emergencies like anti-terrorist laws to shove the Academies Act through parliament in just five working days.

Around half of all children in state-funded schools are now taught by an academy trust. In this new system that is hostile to democracy, one select committee complained in January that “parents and local people have to fight to obtain even basic information about their children’s schools”. And the schools are accountable not to local councillors but only to officials in Whitehall.

It was to those officials at the Department for Education (DfE) that staff and parents at Waltham Holy Cross went, after discovering the most damaging revelation a few weeks ago. Two sets of Ofsted-employed inspectors had visited the primary and found evidence that Net’s English teaching was tantamount to cheating, staff say. In some of the most egregious allegations, it is claimed that Net employees instructed teachers to go through children’s coursebooks and correct spelling and punctuation, using Post-it notes. The children would then copy the corrections, and the Post-its would be binned. According to legal correspondence I have seen, senior Net employees claimed in school meetings that this “helped” the children’s work “look good”.

The allegations were reported twice to Department for Education officials and no material action appears to have been taken. Roberts then found a solicitor to write to Williamson. Government lawyers replied at the end of July saying that, in effect, officials had taken evidence from the head of Net, Jo Coton, and were satisfied there was no charge to investigate. For the next few weeks, Roberts and her lawyer collected evidence from staff at Waltham Holy Cross and other Net academies. They sent a sample of what they had found to the DfE – and last week the government conceded that they would conduct an urgent investigation, during which there would be no transfer. Neither the DfE nor Net will comment on what is now an official investigation, but Net does make the point that “there is no evidence to support the accusation that cheating happens in other Net Academies”.

Roberts’s lawyer at Simpson Millar, Dan Rosenberg, has been an education law specialist for 14 years and has never before seen the government cave in to parents’ demands and call an investigation. He says: “The government’s reflex is normally to back the academy trust over parents.”

Yet this is the kind of amazing victory that shows how much we have lost. While fighting this battle, Roberts and her two boys have been moved through different temporary accommodation four times. She has had to use food banks. She and other parents have stayed up night after night, investigating and organising. And, amid all the uncertainty, the staff at the formerly troubled school have turned it around so that it is bang in line with the national average – even while the British state has given tens of thousands to the incoming trust and to the consultants on the interim board of governors. Barely any of that money has reached the children, of course, but that is perhaps the point of British democracy today: a pantomime of concern, while directing all the power and cash elsewhere.

• Aditya Chakrabortty is a Guardian columnist