As it happened: UK PM sets out 'moonshot' plan for mass coronavirus testing by spring - BBC News
Boris Johnson says it will be a "giant collaborative effort" and hopes it will be widespread by spring.
That press conference can be broken into two parts.

The first is the sombre message - that the virus is increasing again and new restrictions must be brought in for England.

For many people, the limit on social gatherings will be significant and potentially upsetting.

The introduction of nationwide measures is a big deal and something ministers wanted to avoid.

They’re doing it because they’re worried.

At the same time, the PM wanted to inject some optimism.

Boris Johnson is hoping mass tests - maybe daily - could allow people to leave the house in the morning knowing if they are transmitting the virus or not.

That would be a game changer.

But there are significant issues with the testing programme at the moment, and it is far from guaranteed, as the scientists made clear.