Covid-19 deaths could be twice as high over the winter as they were in the first wave of the pandemic, PM Boris Johnson is expected to warn MPs later.
In a Parliamentary statement he will say there is “no alternative” as he seeks to win support for the planned four-week lockdown across England.
But Mr Johnson will explain he was “right to try every possible option” before ordering people to stay at home.
Labour has said it will back the lockdown but criticised the delay.
Mr Johnson announced at a Downing Street news conference on Saturday that strict measures would be imposed across England from Thursday, closing pubs, restaurants, gyms, non-essential shops and places of worship.
However, Housing Secretary Robert Jenrick confirmed that moving house will still be allowed during the restrictions, adding that removal firms, estate agents and tradespeople can continue to work but must follow Covid safety guidelines.
Chancellor Rishi Sunak told BBC Radio 4’s Today programme that the UK-wide furlough scheme, which had been due to end on 31 October, was extended until December “in the interest of simplicity and to give businesses that ease at this difficult time”.
He said it was his “expectation and hope” that the English lockdown would be “sufficient to do the job we need” to “exit back into the tiered approach” in a month’s time.
‘No alternative’
In his address to MPs, due in the House of Commons at about 15:30 GMT, the prime minister is expected to say: “Models of our scientists suggest that unless we act now, we could see deaths over the winter that are twice as bad or more compared with the first wave.
“Faced with these latest figures, there is no alternative but to take further action at a national level.”
Mr Johnson is expected to acknowledge that some MPs believe “we should have reached this decision earlier”, but will defend his earlier policy of trying to control the virus with “strong local action and strong local leadership”.
Prof Andrew Hayward, professor of infectious disease epidemiology at University College London, told BBC Radio 4’s Today programme the forecast death toll data provided to the government included a “range of predictions”.
“From the multiple models they are all really showing unacceptable levels of death and the fact NHS services will be overwhelmed within weeks,” he said.
The prime minister is due to tell MPs that the government will “seek to ease restrictions” on 2 December and return to the current three-tier system.
On Sunday, Cabinet Office minister Michael Gove said the lockdown could be extended if it took longer to bring the transmission rate of the virus down.
Mr Johnson faces a rebellion from several senior Tory MPs, including Sir Graham Brady, chairman of the 1922 Committee of backbenchers, when they vote on the new measures on Wednesday.
Mr Brady told BBC Radio 4’s The Westminster Hour: “If these kinds of measures were being taken in any totalitarian country around the world, we would be denouncing it as a form of evil – and here the removal of people’s fundamental liberties is going almost without comment.”
The “repetitive cycle” of lockdowns was damaging livelihoods, relationships and mental health, Sir Graham said, adding that it was infringing people’s basic rights to freedom of association and family life.
Former cabinet minister Esther McVey said she would vote against the restrictions, adding: “The ‘lockdown cure’ is causing more harm than Covid.
“The world cannot be put on hold, and the government must stop pressing the pause and stop button for the whole nation on a whim, with all the disastrous effects this brings to our lives, livelihoods, health and relationships.”
Former party leader Iain Duncan Smith said the lockdown decision was a “body blow” to people in England and accused the government of “giving in” to scientific advisers.
But the prime minister will have the support of Labour Party leader Sir Keir Starmer, who said the measures were “necessary” while criticising the government for delaying them and ensuring what would be a longer, harder lockdown.
He told the BBC’s Andrew Marr Show “there’s a very human cost to this” after the daily reported deaths rose from 11 on the day in September when government scientific advisers recommended a short “circuit-breaker” lockdown to more than 300 in recent days.
On Sunday, the UK recorded 23,254 new confirmed cases of coronavirus and 162 deaths within 28 days of a positive test.
Elsewhere in the UK, Scotland’s five-level system of Covid restrictions has now come into force.
BBC