Tory plans to stop students with third-class degrees becoming teachers received a withering response from ex-head of JFS, Jo Wagerman. She wrote to The Times to say she had a “third-class degree from night school” yet had become head of “one of the best comprehensives in the country”.

“If Mr Cameron had his way,” she remarked, “I should never have been allowed to teach. I am proud enough to say that would have been not only a great loss for me, but also for all the pupils I taught so happily for more than 40 years.”

It would take a brave politician to disagree.