In a press conference this morning Sir Keir accused Mr Johnson of “gross negligence” and said although his party would support the measures announced yesterday, he said that “yet again, the Prime Minister waited until the 11th hour to take this decision”.
In England, Mr Johnson effectively cancelled Christmas for almost 18m people in London, south-eastern and eastern England as the region was put into a new two-week lockdown from Sunday.
Under the new Tier 4 rules non-essential shops – as well as gyms, cinemas, casinos and hairdressers – have to stay shut and people are limited to meeting one other person from another household in an outdoor public space.
Those in Tier 4 were told they should not travel out of the region, while those outside were advised against visiting.
While those in other areas will be restricted to only forming “Christmas bubbles” with other households for one day on Christmas Day, rather than the previously promised five days.
Sir Keir said: “I think the Prime Minister should apologise. This is not just one mistake when he has otherwise got things right. It is the same mistake over and over again.
“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.”
It comes after Matt Hancock condemned scenes of people crowding into train stations to leave London following the announcement of the latest coronavirus restrictions.
“I think those scenes were totally irresponsible. We have all got a responsibility.
“We in Government of course have a responsibility, but so does every single person,” the Health Secretary told BBC1’s The Andrew Marr Show.
“The plea that I have is that people will play their part, because it is only by acting – all of us – that we can get this under control.”
Mr Hancock rejected suggestions by critics like the senior Tory MP Sir Charles Walker that he could resign.
“I am dealing with a global pandemic in the best way we possibly can, with huge pressures on the NHS, with case rates that are climbing and we must take action no matter how uncomfortable we find it,” he said.
But Sir Keir said: “It was blatantly obvious last week that the Prime Minister’s plan for a free-for-all over Christmas was a risk too far.
“And yet, rather listening to concerns and taking them seriously, the Prime Minister did what he always does: dismissed the challenge, ruffled his hair and made a flippant comment.
“We have known about rising infections and the NHS reaching capacity in many parts of the country for weeks.
“The alarms bells have been ringing for weeks, but the Prime Minister chose to ignore them.
“It is an act of gross negligence by a Prime Minister who, once again, has been caught behind the curve.”
Mr Hancock also suggested this morning that restrictions which forced millions of people across the UK to tear up their Christmas plans may have to remain for “the next couple of months”.
“What is really important is that people not only follow them (the new rules) but everybody in a Tier 4 area acts as if you have the virus to stop spreading it to other people,” Mr Hancock told Sky News’s Sophy Ridge On Sunday programme.
Scientists on the Government’s New and Emerging Respiratory Virus Threats Advisory Group (Nervtag) have concluded the VUI 202012/01 mutant strain, identified by the Public Health England laboratories at Porton Down, is spreading more quickly.
The Prime Minister was advised of the group’s conclusions at a meeting with ministers on the Covid O Committee on Friday evening, and the new regulations were signed off by Cabinet before Saturday’s announcement scuppered many people’s plans to see family for Christmas.
“We know with this new variant you can catch it more easily from a small amount of the virus being present,” Mr Hancock said.
“All of the different measures we have in place, we need more of them to control the spread of the new variant than we did to control the spread of the old variant. That is the fundamental problem.
“We know that because we know that in November that in the areas where this new variant started, in Kent, the cases carried on rising whereas in the rest of the country the November lockdown worked very effectively.
“It is an enormous challenge, until we can get the vaccine rolled out to protect people. This is what we face over the next couple of months.”
Mr Hancock said he hopes 500,000 people in the UK will have received the first of two doses of the coronavirus vaccine by the end of the weekend.
At a No 10 news conference on Saturday, Mr Johnson said he was taking the actions with a “heavy heart”, but the scientific evidence had left him with no choice.
The announcements prompted a rush to the London train stations and by 7pm on Saturday, there were no tickets available online from several London stations including Paddington, Kings Cross and Euston.
Footage posted on social media showed large crowds at St Pancras station waiting to board trains to Leeds.
The Netherlands is banning flights from the UK for at least the rest of the year in an attempt to make sure the new strain does not reach its shores.
It said it will assess “with other European Union nations the possibilities to contain the import of the virus from the United Kingdom”.
The announcements came as a hammer blow to many businesses – particularly retailers hoping to pick up some pre-Christmas sales at the end of a torrid year in which they had faced repeated orders to close.
There was also fury among some Conservative MPs after weeks of growing backbench unrest over the return of more and more stringent controls.
Mark Harper, the leader of the Covid Recovery Group of Tory MPs, demanded the recall of Parliament so MPs could debate and vote on the changes for England.
British Medical Association council chair Dr Chaand Nagpaul however welcomed the announcement which, he said, would save lives and help health services cope with “incredible demand”.