Such is the gap between demand for Covid-19 tests and UK capacity that some tests are being shipped to overseas labs for processing. But even if UK capacity reaches the scheduled 500,000 a day by end of October, and NHS Test and Trace tells me it is on course to hit that...

target (which is double current capacity) there will still be inadequate capacity - which is why the priority for @MattHancock is to prioritise supply to those in healthcare settings, the vulnerable, and vital public services (like schools!), and then screen everyone else...

- probably using GPs as I said yesterday - to eliminate the asymptomatic. But this is a sub-optimal compromise. Because it means some infection will be missed, and there will be increased delays in identifying areas of viral surge. So the goal of controlling the virus only...

through local suppressive measures becomes more elusive.