Paul Ewart, a distinguished member of Oxford’s physics department, had no desire to leave when he reached the university’s then mandatory retirement age of 67 (it has since been raised to 68). He applied for a two-year extension, which he received. At the end of that he applied for a further extension and was refused. So he sued Oxford for age discrimination and won.

Age discrimination is illegal in the EU. But unlike other forms of discrimination, such as race or gender, age discrimination is allowed if it can be “objectively and reasonably justified by a legitimate aim”. Oxford said that its mandatory retirement age, and its caution about extending it, was justified on several counts, including “intergenerational fairness”, or opening up opportunities for younger academics, and promoting diversity — old professors were more likely to be male and white than those angling to replace them.

The UK employment tribunal dismissed these arguments at the end of 2019. There were ways to create vacancies other than compulsory retirement, it said. The increase in vacancies generated by forcing older academics out was “trivial in comparison with the discriminatory effect”. And there could hardly be anything more discriminatory than “being dismissed simply because you hold a particular?.?.?.?characteristic”.