BORIS Johnson has called on Britons to be vigilant in the fight against coronavirus, insisting now was not the time to be “taking our foot off the throat of the beast”.

At a Downing St press briefing the Prime Minister urged people to “keep our eye on the prize” as he said he was now convinced, with the approach of a vaccine, that “by April, things genuinely will be much, much better”.

His remarks came as some 23 million people - 40 per cent of England, including much of the north west, north east and the Midlands - were placed under the severest Covid-19 tier restrictions, following a lockdown, threatening a largescale Tory backbench rebellion when the matter comes to a vote next week. One Conservative former minister accused Mr Johnson of “appalling authoritarianism”.

At the No 10 press conference, Mr Johnson, who had emerged earlier in the day from a two-week self-isolation period, said that with increased community testing and vaccines there was real hope that by spring the “era of restrictions” would be over.

“But to get there we must first navigate a hard winter when the burden on our NHS is heaviest and the cold weather favours the virus,” he insisted.

The PM called on people to stay focused and not ease up, noting: “Remember, in a few months we will have a vaccine; I’m convinced of it now…By April, things genuinely will be much much better but what we want to avoid is relaxing now too much; taking our foot off the throat of the beast now when we’ve got it in a much better place than where it was before the autumn measures came in.”

At the press conference, Professor Chris Whitty, the Chief Medical Officer for England, urged people to “buy into” the cross-border Christmas strategy but “not do stupid things”.

“We can see an end to it but the end is not now,” he declared.

Prof Whitty stressed people should enjoy a family Christmas but added: “Would I encourage someone to hug and kiss their elderly relative? No, I would not. It’s not against the law. You can do it within the rules that are there but it does not make sense because you could be carrying the virus…”

Mr Johnson defended a return to the tiered approach south of the border, which he said had been delivering. “It was slowing the virus down and that’s why a tiered, reasonable approach is the right way to go now,” he insisted.

However, the sound of rebellion was growing on the Conservative backbenchers.

Steve Baker, leader of the Covid Recovery Group of lockdown sceptics, said: “The authoritarianism at work today is truly appalling. But is it necessary and proportionate to the threat from this disease?”

Senior Tory colleague Sir Graham Brady, who chairs the 1922 backbench committee, echoed the sentiment and made clear he would vote against the proposals in the Commons next week.

“I have severe reservations on so many different levels. I do think that the policies have been far too authoritarian,” declared the Cheshire MP.

Other rebels included former minister Tobias Ellwood, the MP for Bournemouth East, who tweeted: “With only 160 cases per 100k I’m puzzled to see us placed in this tier which will cause further hardship for our hospitality industry. I will NOT be supporting the Gov’s motion to introduce this next week.”

The MPs for North Somerset and Weston-super-Mare said the decision to place the area in Tier 3 was “not right nor fair”.

In a joint statement, Dr Liam Fox and John Penrose said: “On our own, North Somerset might well qualify to be in Tier 2, but we have been placed in Tier 3 because we are regarded as ‘a natural travel to work area’ along with Bristol and Gloucestershire.”

They said the decision was “illogical” given that people have been asked to work from home and said the region was being punished for higher infection rates in Bristol.

Some Tory MPs questioned the impact of the recent national lockdown, with some areas leaving the circuit-breaker under tougher restrictions than they had entered it.

Tom Tugendhat, who represents Tonbridge, Edenbridge and Malling in Kent, said: “We went into lockdown at Tier 1 and came out at Tier 3. This isn’t working for us.”

Jonathan Djanogly, the MP for Huntingdon in Cambridgeshire, tweeted: “My constituency went into second lockdown[against my wishes] at Tier 1 and, with great cost to the Hunts local economy, has come out of lockdown at Tier 2 – am I missing something here! I will need to have this justified before voting for it.”

West Worcestershire MP Harriett Baldwin said: “Over 23 million of us were living under Tier 1 restrictions before the lockdown – that figure will be under one million in December.

“There is no logic whatsoever in having a month of lockdown only for people to have to live under an even more severe set of restrictions afterwards.”