The rapid spread of a mutated strain of the COVID-19 virus prompted an immediate decision on Saturday, by the UK government, to put London and South East England into new Tier 4 restrictions...technically a lockdown.
This means that persons in those areas are barred from mixing households and are restricted to leaving their homes for only essential reasons.
The decision announced by Prime Minister Boris Johnson came just days after he spoke of “having a small Christmas” and suggesting that it would be “inhuman to cancel Christmas”.
But on a cold and dreary Saturday afternoon in the UK that was the tiding of not great joy that the Prime Minister brought in the wake of evidence that a new strain of the virus was spreading rapidly.
“It is with a heavy heart that I must tell you we cannot continue with Christmas as planned," Mr Johnson intoned at a news conference on Saturday.
Wales and Scotland, which have their own governments, also announced tighter restrictions on Saturday with Wales going into a full lockdown from Saturday night.
Earlier in the week, Mr Johnson resisted calls to tighten the measures in place then, in which some parts of London and elsewhere in England were under Tier 3 allowing some minimal mixing of households for the Christmas period.
With areas in Tier 4 now required to stay at home, the previous five-day easing of restrictions over the festive has now been limited to one day for the rest of England.
He said then that people should exercise personal responsibility, minimise social contacts, and delaying visiting elderly relatives until after they have been vaccinated.
However, with concern over the new strain of the COVID-19 virus said to be responsible for a spike in cases the abrupt announcement came late on Saturday afternoon (UK time) to impose the harsher measures.
It is also presently uncertain how effective the new vaccines now being rolled out against the original strain of COVID-19 will be against the new mutation.
Mr Johnson has been criticised for not acting sooner and there are calls for the UK Parliament to be recalled from its Christmas vacation to debate the current crisis.