A senior Tory has accused Boris Johnson of deliberately waiting to announce Tier 4 until after MPs went home for Christmas.
Charles Walker, Vice Chair of the 1922 Committee of Tory backbenchers, claims the Government knew it intended to 'cancel' Christmas Bubble plans and introduce tougher restrictions on Wednesday.
Number 10 has insisted the decision to change advice and introduce tougher restrictions in London and the South East was only taken after new data on a mutated strain of Covid-19 was seen by the PM on Friday night.
But Mr Walker told the BBC's The World This Weekend: "I suspect the Government knew they were going to cancel Christmas on Wednesday and Thursday when they were still telling the House of Commons they planned to press ahead,
"I think many colleagues find that extremely egregious. The Christmas period was passed into law by the House of Commons in a vote after a debate.
"The view of most colleagues was that to be changed, another vote would be required in the House of Commons. So I suspect a decision was delayed until we were safely away back to our constituencies."
He added: "Surely at some stage a senior Government minster has to say 'I have offered my resignation to the Prime Minister' and the Prime Minister has to say 'Sadly I have had to accept it'?"
Health Secretary Matt Hancock this morning insisted the Government had acted "very quickly and decisively" after ministers were told on Friday by scientists on the Government's New and Emerging Respiratory Virus Threats Advisory Group (Nervtag) that the VUI 202012/01 strain was spreading more quickly.
However, Sir Keir said the alarm bells had been "ringing for weeks" but that Mr Johnson - who said on Wednesday that it would be "inhuman" to cancel Christmas - had repeatedly failed to act.
"It is an act of gross negligence by a Prime Minister who, once again, has been caught behind the curve," he told an online press conference.
"At the heart of the problem here is a Prime Minister who simply doesn't want to be unpopular and therefore won't take the tough decisions that are necessary until he is forced into them at the 11th hour.
"We can't go on like that. I think that it is very important that the Prime Minister does apologise to people for his handling of this episode of the pandemic."
