Video report by ITV News Correspondent Carl Dinnen
Boris Johnson has been accused of being "behind the curve again" over his decision to reject a new, short national lockdown, as Sir Keir Starmer continued his calls for a "circuit breaker".
Sir Keir, referencing minutes from a meeting of the government's Scientific Advisor Group for Emergencies (Sage) in which the government was advised to impose a circuit break, asked: "Why did the prime minister reject that advice and abandon the science?"
The prime minister insisted his "regional approach" can "bring down the R and bring down the virus," but the Labour leader hit back by saying even Chief Medical Officer Chris Whitty is "not confident" the new three tier alert system will work.
ITV News Correspondent Rebecca Barry reports from Manchester where tensions are growing between local leaders and Boris Johnson's government:
The prime minister said nobody in the UK wants to a see a return of "the disaster of a national lockdown" and he'll "do whatever it takes to fight this virus and to defeat" Covid-19.
But Sir Keir said a circuit-break is in the "national interest" and the government's two main policies - track and trace and local restrictions - "simply haven't worked".
In a tense session of Prime Minister's Questions, Mr Johnson accused Sir Keir of performing an "extraordinary U-turn" by backing a circuit break, adding: "opportunism is the name of the game for the party opposite".
Sir Keir responded: "I know that for someone who has been an opportunist all his life this is difficult to understand, but having read and considered the Sage advice I have genuinely concluded that a circuit-break is in the national interest - genuinely concluded."
Mr Johnson said the "whole point" of his regional approach is to "seize this moment now to avoid the misery of another national lockdown into which he wants to go head-long by delivering a regional solution".
He said Sir Keir "wants to close pubs, he wants to close bars, he wants to close businesses in areas across the country where the incidence is low.
"That is what he wants to do, and he wants to do it now and yet he voted to do nothing last night, nothing in the areas where the incidence is highest."
He insisted three tiered support is "right way forward", adding "we want to put in the most stringiest measures necessary in the places where the virus is surging".
The prime minister hinted he could impose a new national lockdown at some point but he appeared committed to more targeted restrictions.
He said: "I rule out nothing, of course, in combating the virus but we're going to do it with the local, regional approach that can drive down and will drive down the virus if it is properly implemented."
The Labour leader says he wants a short lockdown to bring down infection rates and allow the government time to get its coronavirus testing strategy in order.
The prime minister rubbished criticisms of the UK's testing system, saying Britain is "testing more than anywhere else in Europe".
Sir Keir Starmer and Boris Johnson are currently locked in a tense stand off amid calls for a circuit break lockdown to be implemented for two weeks to stem the spread of coronavirus.
The scene was set for a fiery PMQs after Sir Keir held a press conference on Tuesday night demanding that Mr Johnson impose a fresh lockdown.
Following the press conference, senior Tory sources told journalists Sir Keir is a "shameless opportunist" and accused him of "playing politics" with his calls for another lockdown.
Instead of imposing another national lockdown, the PM introduced a three-tier alert system for local lockdowns - medium, high and very high.
ITV News Correspondent Damon Green has the latest on the impact of restrictions in Liverpool:
The new system of coronavirus restrictions for England came into effect on Wednesday, but the Liverpool region is the only area to be under the toughest rules.
The government is still locked in talks with councillors in Greater Manchester and Lancashire on whether to classify the areas as "very high", which would see all but essential businesses closed.
Watch PMQs in full: