Video report by ITV News Political Correspondent Carl Dinnen
Boris Johnson has refused to rule out tightening rules under England's lockdown, as First Minister Nicola Sturgeon announced lockdown measures were being ramped up in Scotland.
Mr Johnson said the current lockdown measures "are starting to show signs of some effect" but he refused to rule out stricter rules, saying restrictions are kept "under constant review".
He added: " If there is any need to toughen up restrictions, which I don't rule out... We will of course come to this House."
Sir Keir said it is "likely" that within the next fortnight the prime minister will be asking MPs to vote on stricter lockdown measures.
Minutes later Ms Sturgeon announced rules were tightening in Scotland, with most click and collect services being banned, along with alcohol consumption outdoors in all Level 4 areas.
Scots will also be barred from entering hospitality businesses for takeaway services, Ms Sturgeon said, meaning all takeaway sales of food or drinks must take place from outside the premises.
She added that statutory guidance would now be introduced urging employers to support workers to remain at home "wherever possible".
She told MSPs regulations would be changed, forbidding people from leaving home for an essential purpose and then doing something considered not to be essential after they have left the house.
In another feisty session of Prime Minister's Questions, Labour leader Sir Keir attacked the PM for making "late" decisions, as he insisted "stronger restrictions are needed" to bring down infection rates.
He told the Commons: "Every time there's a big decision to take, the PM gets there late .
"The next big decision is obvious; the current restrictions are not strong enough to control the virus - stronger restrictions are needed."
He demanded the prime minister explain why England's third lockdown is less strict than the first, given "infection rates are much higher than last March... Hospital admissions are much higher than last March" and "death rates are much higher than March".
"Why on Earth are restrictions weaker than last March?" he asked.
Mr Johnson accused the Labour leader of having no other policy than "to plunge this country into 12 months of lockdown".
"No one can doubt the serious damage that is done by lockdowns to people's mental health, to jobs, to livelihoods as well."
The prime minister admitted the UK is facing the "toughest of times", made worse by the new, fast-spreading variant, but said vaccines present a "way forward".
Dame Cressida Dick, commissioner of the Metropolitan Police, told ITV News of how the force will be helping London Ambulance Service during the second wave
Sir Keir and Mr Johnson also traded barbs over free school meal parcels, which resulted in the prime minister being told off by the Speaker of the House.
Mr Johnson condemned some free school meal offerings as "disgraceful" after images were shared on social media, but Sir Keir suggested the PM was to blame.
After reading out government advice on what a free school meal parcel should contain, Sir Keir said: "The only difference I can see in this list and what the Prime Minister has described as disgraceful is a tin of sweetcorn, a packet of ham and a bottle of milk.
"So, he blames others but this is on his watch. The truth is families come last under this Government, whether it's exams, free school meals or childcare."
Mr Johnson was slapped down during his response by Speaker Sir Lindsay Hoyle for describing his rival's words as "hypocritical", saying it was a policy brought in by a Conservative government.
The Speaker said: "Please, let's keep the discipline in this chamber and the respect for each other. We're tidying up how this Parliament behaves and I certainly expect the leadership of both parties to ensure that takes place."
Mr Johnson took the advice to withdraw the claim of hypocrisy and highlighted the "absurdity" of Sir Keir attacking the government on free school meals given policies put in place by the Conservatives on the issue.
Watch Boris Johnson and Keir Starmer at PMQs: