To get a measure of the Dominic Cummings affair, it may be useful to imagine and compare two scenarios. One, where Mr Cummings hangs on despite the bad publicity and resumes his role devising the core policies of Boris Johnson’s Government; the other, where he leaves his job as chief adviser to the Prime Minister and becomes a private citizen.

What is immediately apparent from this comparison is the extent to which Mr Cummings has become indispensable to the Johnson project. Since entering 10 Downing Street he has overseen an unprecedented revision to the structure of government, and has placed himself at the middle of the Whitehall policy spider’s web. He has centralised power into his own hands, even telling cabinet ministers – by vetoing the appointment of any political advisers he disapproves of – to whom they may or may not turn for advice. At the same time Mr Johnson, advised by Mr Cummings, has carefully picked as his key ministers inexperienced individuals who are prepared to suppress their own opinions and personalities for the sake of high office. They are, as one ex-minister put it, a collection of nodding donkeys.