THE prime minister is under pressure as scientists say a "circuit breaker" lockdown could save thousands of lives. 

As the three-tier Covid system starts today across England, Boris Johnson is facing calls to put a fortnight of lockdown restrictions in place to get the second wave of the coronavirus crisis under control. 

It emerged he dismissed a recommendation for the measure from government scientists three weeks ago.

Labour leader Sir Keir Starmer said a two to three-week national lockdown over the October half term was needed to prevent a “sleepwalk into a long and bleak winter”.

Sir Keir said: “There’s no longer time to give the Prime Minister the benefit of the doubt. The Government’s plan simply isn’t working. Another course is needed.”

He said schools must stay open but all pubs, bars and restaurants should be closed during the circuit-breaker while firms are compensated.

A paper by members of the Scientific Advisory Group for Emergencies reportedly calculates that more than 7,000 lives could be saved if schools are closed and people are ordered to stay at home from October 24 for two weeks.

Sage delivered a series of more drastic recommendations than the new three-tier system Mr Johnson has proposed.

Scientists also criticised the Government’s £12 billion test and trace system as only having a “marginal impact” on Covid-19 transmission.

It comes as the UK recorded the highest daily death figure in four months, with a further 143 people dying within 28 days of testing positive for Covid-19 as of Tuesday.

The prime minister is reportedly open to putting the two-week lockdown in place if the three-tier system fails, according to the Mirror.

Health Secretary Matt Hancock said the three-tiered system of local lockdowns was needed to prevent more severe restrictions and spiralling deaths as he opened the Commons debate.

“And in addition, then, harder economic measures would inevitably be needed to get it under control and needed for longer,” he said.