For Sir Michael Wilshaw, whatever teachers do, it’s not enough; however well they do it, it’s not good enough; and whatever sacrifices they and their families make, that’s not enough either.

Although teaching has tens of thousands of conscientious, honourable and hard-working practitioners, education is the most corrupt institution I have ever worked in. It runs from the government and Ofsted’s absurdly unmeetable demands and mobile goalposts right down to the wretched teachers who do whatever they have to in order to save their own necks.

No teacher would ever expect pupils to work harder or do better under the sort of tirade Sir Michael has just come out with, so why on earth does he think teachers will? This otiose windbag is sowing the seeds of his own destruction. He is a spent force because it is people like him who drive the corruption.

Guy de la Bedoyere, Welby, Lincolnshire.