The police’s logic will presumably have been, first, to establish whether particular social gatherings in Downing Street were against the Covid regulations and then, second, to catch in the net of fixed penalty notices all those who can reasonably be considered to have attended.

So far, so obvious – but the police appear to be taking a severe view of attendance, if Rishi Sunak is effectively being fined for having been briefly present at a surprise Number Ten birthday event for Boris Johnson after entering Number Ten for a Covid meeting.

Perhaps the penalty notice relates to another event altogether.  If it doesn’t, a question arises: was the Prime Minister also fined for being at the same event?  If so, could he have had more than one fixed penalty notice?  (By the way, Carrie Johnson has also reportedly had one.)

The expectation since the Ukraine war began is that there will be no leadership challenge to Johnson until after the local elections at least.  We will now find out whether it is correct – and what difference the Chancellor’s removal as a prospective successor, at least for the moment, makes to the odds of a challenge.

For that he has received a penalty notice surely rules him out of any contest soon if the row about his wife’s tax status had not one so already.  There will be MPs in all parts of the Commons who’ve received such notices themselves – for parking offences, say.

But it is a very big thing for the two most senior Ministers in government, the Prime Minister and the Chancellor, to have received such notices.

We are about to discover whether either will seek to appeal in some way: it looks as I write as though the news has leaked without Number Ten being told the details…

…And what view Tory MPs will take of the notices in the midst of an international crisis and during the run-up to the local elections when Parliament returns next week.