That Matt Hancock has gone down with the virus too is in some ways more of a poser than the Prime Minister falling ill.

The Health Secretary chairs one of the four Cabinet committees tasked with responding to the virus. And is in charge of the push to roll out testing and equipment.

Edward Argar, Minister for Health, will be across a lot of the detail, and is best placed to take over, perhaps under the supervision of Michael Gove, who will be standing in for Boris Johnson at the daily press conferences.

It may be that Hancock is able, like the Prime Minister, to continue working by video link.  Best wishes to him, and we add the names of any further senior Ministers who are announced ill today to this post.

4.45 Update: Chris Whitty, the Chief Medical Officer has tweeted that “after experiencing symptoms compatible with COVID-19 last night, in line with the guidance, I will be self-isolating at home for the next seven days”.