The triggering of major incident status – defined as a situation requiring a special response by the emergency services – came the day after Sussex and Surrey took the same step. It was previously triggered in the capital after the London Bridge terror attack and the Grenfell Tower fire disaster, both of which happened in June 2017.
The latest NHS Test and Trace data shows that people with the UK variant pass the virus on to 15 per cent of their close contacts, compared to just 11 per cent for those with the original virus.
A source close to the Government said: “With the increased transmission, the measures won’t slam the ‘R’ down as effectively as they did in March so it may look a bit flatter. We may well stick at a plateau for quite a long time, rather than a peak and decrease.
“Once all the care homes are vaccinated, you would expect the death rate to come down, maybe in February some time, and you might expect to see that from the hospitalisation a bit later.
“If the vaccination programme rolls out really effectively and the vaccines behave as well as they’ve done in trials, then you start to see a real opportunity to start easing things off a bit over the summer and spring.
“But then you may need to have something reintroduced next winter and you think about things like mask wearing and social distancing to make sure that we don’t we don’t give the virus a chance to spread again.”
New data from PHE shows the UK variant is now the dominant strain in Britain, accounting for 80 per cent of all cases.