There weren’t going to be many surprises in the official new rules. We have known what Plan B entailed for quite a long time: more mask-wearing, less going into the office but no social distancing and no lockdown. It may have been depressing but it wasn’t shocking. The only question that mattered hung over the event like a pall: does the Government, and most specifically, the Prime Minister, now have the moral authority to make any rules at all?

Predictably enough, that is all the assembled journalists really wanted to know, and they asked, in their myriad different ways, precisely that over and over again. Would public forbearance and cooperation finally be exhausted in the face of what appeared to be Downing Street’s own cynical disregard for the restrictions it had imposed on the country? Indeed, has the population become so sceptical and disillusioned by the display of flippancy that it has witnessed, as to assume that even this very press conference might be a deliberate political tactic to bounce the headlines in another direction?

Faced with that accusation, Boris Johnson gave a clever but not necessarily convincing reply: imagine the counterfactual, he said. What if we had decided to delay the announcement of these new measures purely because we were caught up in  a bad news storm. Surely that would have been utterly irresponsible. So he asked us to believe what might very well be true: that the decision to move to Plan B could not be delayed any longer for substantial medical reasons, so the decision to announce that move today was essential and right. (And, as he did not say, quite personally brave since it involved him being exposed to the interrogation of journalists at a very unfortunate moment.)

Well, perhaps that is the case. The problem is we will never be sure. What has happened over the past 24 hours has damaged the credibility and the perceived trustworthiness of the Government so deeply that it may well have forfeited its right to impose restrictions on personal behaviour for the foreseeable future. 

It will not do, to act as if this is simply a grotesque embarrassment or a crass reminder of just how insensitive people in governing circles can be. The substantive fact here is that staff employed by Downing Street appear to have broken rules laid down by their own Government. If that proves to be true then their boss, the Prime Minister, must accept ultimate responsibility. It is not sufficient to throw Allegra Stratton (or to allow her to throw herself) under the bus.

Does the Prime Minister take the regulations that he is imposing on an astonishingly conscientious country seriously, or not? Even assuming that he genuinely believed the additional measures in Plan B to be absolutely imperative at this exact moment, it takes a hell of a lot of nerve to demand that we all follow them without doubt or question. The days of that sort of confidence may be gone for good.