The Downing Street resignations give rise to an obvious question: what are Tory MPs waiting for?

So, we didn’t need to wait for Sue Gray after all. The mantra, repeated ad nauseam by the prime minister and his defenders for many weeks, is all too familiar.

No action concerning the breach of lockdown laws could be contemplated before all the facts were ascertained by Ms Gray – not just those contained in the “update”, duly placed in the public domain – nor before the police had completed their own enquiries and issued either penalty notices or proceedings.

This process was supposed to take weeks, while in the meantime some useful administrative reforms in Downing Street could be organised: all very slow-moving and undramatic. Instead, we have experienced another 24 hours of panic, chaos and disorder.

Five of Boris Johnson’s closest staff have now departed, or will shortly do so. Some were expected to, in the light of what we already know about the “culture” of Downing Street, such as the prime minister’s principal private secretary, Martin Reynolds, his head of communications, Jack Doyle, and his chief of staff, Dan Rosenfield.

But the clear-out came much sooner than the nation had been led to expect – and obviously without waiting for Sue Gray’s report or anything else. It seems that the “update” itself, along with the knowledge the prime minister personally carries, was sufficient to prompt their hasty resignations.

The other two recent departures were more surprising, and probably more damaging: Munira Mirza, head of policy, who objected to the senseless smear about Jimmy Savile that was thrown at Keir Starmer during Prime Minister’s Questions on Wednesday; and now her colleague, Elena Narozanski.

These are not in the same category as the others, but they add to an impression – and the reality – of a Downing Street that is being steadily hollowed out. Of Mr Johnson’s principal lieutenants, only the cabinet secretary is still in place (for now), and he is also compromised, as is Carrie Johnson. Things must be getting lonely for the prime minister.

An obvious question arises: if the resignations of these Downing Street staffers did not need to wait for Sue Gray, why do Tory MPs have to wait before they make their minds up about Mr Johnson? Even if they don’t know everything, they do know enough now about what happened in Downing Street, and the prime minister’s involvement in it, to form a view of him. They also have the Owen Paterson affair to reflect on, and various other sleazy scandals for which Mr Johnson has been personally censured.

Backbenchers and ministers alike have the experience of the past two years of Johnson rule to help guide them, and as good an idea as anyone of what the prime minister wishes to achieve in the coming years. They know his character, his reputation with the public, his strengths and weaknesses, and whether he can lead. They do not need Sue Gray or the Metropolitan Police to enlighten them about the broader political scene.

The public don’t trust the man; Labour has a ten-point lead; and the Tories have lost two safe seats to the Liberal Democrats. They need not wait to send their letters of no confidence to Graham Brady, and, according to the rumours, soon enough they will have done so in sufficient quantities to trigger a vote of confidence. That may well come before Sue Gray and the police make further announcements.

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For many, even if Mr Johnson were to be completely exonerated, what they know of him now would be enough for them to want a new leader.

Mr Johnson has told his dwindling band of support staff: “As Rafiki in The Lion King says, change is good, and change is necessary even though it’s tough. We’ve got to get on with our job of serving the people of this country.” It doesn’t sound entirely appropriate, given the circumstances.

The change that they, along with the country as a whole, are really waiting for is becoming increasingly obvious – even to the prime minister – and indeed, inevitable. Mr Johnson may well be gone before he gets his fixed penalty notice from the police. It’s tough, but probably just as well.