In saying, as she did in her closing address to the Association of Teachers and Lecturers this week, that UK schools were stratified along class lines, with "toxic" consequences for the poor, Dr Mary Bousted might have meant to shock. But she was articulating a highly uncomfortable truth. A cumulative effect of comprehensive education over 40 years has been the determinism of the catchment area. Children brought up in more affluent areas receive, by and large, a decent education. Those who grow up on the wrong side of the tracks can find themselves trapped in poorly performing schools, so that disadvantage is heaped upon disadvantage.

Parents know this full well, which is why house prices close to good schools command a premium, why parents with money gravitate to such areas, and why the benefit that children from poor backgrounds might have hoped for from the end of 11-plus selection has often not materialised. On the contrary, it could be claimed, with the escape route of a grammar-school education closed off, the opportunities for bright but poor children have been reduced. For schools, the need to retain their prestige – and their relatively advantaged pupils – is why they pay such attention to league tables and stop at little to keep their grade scores up.

Dr Bousted also deserves credit for focusing on the plight of children. Her approach offered a refreshing change from the introspective litanies of complaints about pay, pension contributions, working hours, and the rest, that poured forth from the two main teachers' unions yesterday and will doubtless continue through this conference weekend.

The class divide penalises many children, but the interminable threats of industrial action that the big teachers' unions routinely bandy about at this time of year hardly suggest a profession that always has the best interests of pupils at heart. But the leader of the ATL had another reason, too, for drawing attention to the role of class in the school system. She used it to question the blame that invariably attaches to teachers at poorly performing schools.

Again she had a point. League tables are a narrow gauge of achievement. By no means all schools with a poor showing in the league tables are bad schools. Many have able teachers who demonstrate heroic commitment, but their efforts will never reap the same results, on paper, as those achieved at the more privileged establishment up the road. There are bad teachers, of course, but the effects of deprivation cannot just be wished away.

Which is where we have to part company with Dr Bousted and probably with the many other teachers' representatives we will hear from in coming days. Their case is that the Government has chosen to pillory teachers rather than address the deeper-seated social causes of failing schools. But there are limits to what education ministers can do to tackle entrenched social problems, while there are measures they can take to raise school standards. And the fact that some teachers feel threatened by them does not automatically make such measures wrong.

Michael Gove has come in for much flak as Education Secretary, and he has not always been well supported, it seems, by his civil servants. But in demanding better-qualified teachers, toughening the inspectorate, loosening the stranglehold of local authorities by speeding the creation of academies, harnessing local activism by encouraging free schools, imposing a new core curriculum, changing the scoring system for league tables, and moving towards reform of A-levels, he has at least shown himself prepared to tackle some of the identifiable ills that afflict our schools. That much of what he is doing clearly discomfits the teachers' unions should not deter him. Many parents – including those on the wrong side of Dr Bousted's class divide – will, rightly, be cheering him on.