Britain is not "Officially" closed yet. Schools are still open but people are being asked to self-isolate if they have come into contact with a possibly-infected person or are showing symptoms.
Large gatherings have been postponed/cancelled.
The strategy, if one can call it that, is to get the majority of the population immunised through contact - the so-called 'Herd Immunisation'. Losing a few thousand chronically sick along the way will reduce the load on the NHS (cynical, moi ?).
Leaving the instructions as 'requests' rather than 'Government Decree' prevents Businesses from claiming on Insurance . . . .
Gotta love Politicians.
My avatar shows the late Len Rich in 1970 with the bike I now have - a 1958 Ariel VH