The Christmas lockdown relaxation has been cut from five days to one day, so three households can meet only on December 25.
Prime Minister Boris Johnson announced the reduction on Saturday afternoon as a new variant of the COVID-19 virus is now taking hold of the UK.
The mutation is up to 70% more infectious — but not more dangerous or deadly so far. There’s no evidence the vaccine is less effective either, he said.
Full tier 3 lockdown rules, which include no households mixing, will apply on New Year’s Eve too, as the PM urged to avoid celebrations.
A new tier 4, similar to the November national lockdown, will be introduced from Sunday morning in London, the South East and Peterborough, closest to Lincolnshire.
Tier 4 means all non-essential shops, hospitality and leisure centres must close.
There is also new advice on travel affecting Christmas —everyone should stay local in all tiers and avoid travelling abroad, with tier 4 not allowed to travel.
The next review of the tiers will be on December 30.
Boris Johnson said: “Without action, the evidence suggests that infections would soar, hospitals would become overwhelmed and many thousands more would lose their lives.”