He is also right. The misty-eyed nostalgia for grammar schools that has surfaced during the past week typifies all that is worst about English debates on education. For more than half a century, we have argued about school organisation when we should have been thinking about raising standards in all classrooms. We have talked about ensuring that bright children, especially working-class ones, get academic opportunities, when the real problem with our schools is that those at the bottom of the heap lag further behind those at the top than in most other developed nations.

If the notion that grammar schools offered a helping hand to working-class children was ever true, it certainly is no longer the case. In the 19 counties with significant numbers of grammars, just 2 per cent of their pupils are on free school meals.

The political case against grammars has always been about the pupils who don’t go there. Labour demolished John Major’s promise of “a grammar school in every town” by asking which school in each town would be the secondary modern? In the days of the nationwide 11-plus, between 20 and 30 per cent of children went to grammars. But voters soon wised up to the fact that this was a system in which three-quarters of children were destined to be second-class citizens.

It is bizarre that 164 schools - the only remaining grammars - have thrown the Conservatives and their media supporters into turmoil. They should be thinking, as Cameron says, of the 355,000 pupils who fail to achieve five good GCSEs. If his party cannot support him, they don’t deserve to be in government.