As claims about practices in two flagship London schools are investigated, it’s time to stop and think about what schools are really for

Ask the average Westminster politician about schools policy and the response will focus on issues that never seem to go away: funding, teacher shortages, and the drive to somehow uncouple unequal educational outcomes from children’s social and economic backgrounds. At the moment the stereotypical answer is likely to also touch on the crisis in provision for kids with special educational needs. But what tends to go unmentioned is a subject that seems to be suddenly gaining traction in the real world: many schools’ devout belief in zero-tolerance discipline, and whether that credo might be on its way out.

Across England, the same story has been building for a long time. It originated in the New Labour years with the expansion of academies, the cult of the “super head” and a seemingly rational drive to push up results and standards. During Michael Gove’s time as the Tory education secretary and beyond, the same ideas fused with drastic changes in the national curriculum and a belief in quietening schools using old-fashioned punishment. And soon enough, the downsides of those approaches began to surface: eye-watering numbers of kids either suspended or excluded by their school, the grim use of isolation booths and claims that the transfer of so many former council-maintained schools to multi-academy trusts (Mats) had led to a deep crisis in accountability.

John Harris is a Guardian columnist