Boris Johnson has set out new emergency measures to control the spread of coronavirus in England.

The tightening of restrictions announced by the Prime Minister this evening is in response to the “rapidly escalating” numbers of infections following the emergence of the new variant.

Today's statement is to be followed by the recall of Parliament on Wednesday so MPs can debate the measures.

Mr Johnson said latest restrictions - which have been introduced following the discovery of the "alarming" new variant of the disease - are similar to those that were in place for the first lockdown in March.

The Tory leader said: "Our hospitals are under more pressure from Covid than at any time since the start of the pandemic.

"The number of deaths is up by 20% over the past week and will sadly rise further.

"It's clear that we need to do more together to bring this new variant under control in England. We must therefore go into a national lockdown.

"That means the government is once again instructing you to stay at home."

Under the new restrictions, residents are instructed to only go outside if they are unable to work from home, need to buy groceries, seek medical advice, exercise or to escape domestic abuse.

The Prime Minister said the clinically vulnerable must shield again and will soon receive a letter detailing how the changes will impact them.

All schools and colleges will move to remote learning from tomorrow, amid fears classrooms could "act as vectors for transmission" of the virus.

Mr Johnson conceded that the closures mean that it is no longer "possible or fair for exams to go ahead this summer".

He added that Education Secretary Gavin Willamson is working with Ofqual to put in place alternative arrangements.

"I completely understand the inconvenience and distress these changes will cause to millions of parents and pupils up and down the country," the Prime Minister continued.

"We did not make this decision sooner because we have been doing everything within our powers to keep schools open because we know how important each day in education is to children's life chances.

"I must stress that the problem is not that schools are unsafe for children - they are still very unlikely to be severely affected by even the new variant of Covid - the problem is that schools may nonetheless acts as vectors for transmission, causing the virus to spread between households."

Reacting to the announcement, Tonbridge MP Tom Tugendhat welcomed the change to change to assessments, noting that it will help youngsters "have confidence their achievements will be judged on their merit".

The Conservative leader also revealed that chief medical advisers warned him earlier today that "if action is not taken, NHS capacity may be overwhelmed within 21 days".

"Of course, there's one huge difference compared to last year, we're now rolling out the biggest vaccination programme in our history," he added.

"So far, we in the UK have vaccinated more people than in the rest of Europe combined.

"By the middle of February, if things go well, we expect to offer the first vaccine dose to everyone in the four top priority groups.

"That means vaccinating all residents in a care home, everyone over the age of 70, all frontline health and social care workers and anyone who is clinically extremely vulnerable.

"That will eventually enable us to remove many of the restrictions we have endured for so long."

Despite urging caution, Mr Johnson said that, if the vaccine programme proves a success and if deaths start to fall, he hopes "to steadily move out of lockdown [and] reopen schools after the February half-term".

"This is a pivotal moment," he stated.

"The weeks ahead will be the hardest yet, but I really do believe that we're entering the last phase of the struggle because every jab that goes into our arms is tilting the odds against Covid and in favour of the British people.

"Thanks to the miracle of science, not only is the end in sight, but we know exactly how we will get there."

Meanwhile, the country's Covid alert level has been moved up to five due to the risk of healthcare services becoming overwhelmed.

The move comes as Nicola Sturgeon announced Scotland will go into lockdown for the rest of January with a legal requirement to stay at home and schools closed to most pupils until February.

Setting out the measures to come into force from tomorrow, the First Minister told MSPs in Holyrood: “It is no exaggeration to say that I am more concerned about the situation we face now than I have been at any time since March last year.”

Earlier, during a visit to a vaccination centre in north London, Mr Johnson acknowledged there was “no question” the further measures would be necessary, as cases continue to surge across the country.

The latest data shows a 41% rise in the number of confirmed coronavirus patients in hospital in England between Christmas Day and January 3, figures which have caused alarm in Whitehall and the health service.

While ministers hailed the rollout of the new Oxford-AstraZeneca vaccine, Mr Johnson warned the nation needed to prepare for some “tough” weeks ahead as the jab was extended to the most vulnerable.

And infection rates in Kent look set to reach a pandemic high after new case numbers hit record levels four days after Christmas.

Positive tests had fallen week-on-week over the festive period, giving hope that the county had turned a corner in the fight against the virus.

But latest figures indicate the drop in rates was largely due to a huge fall in the number of people getting tested over the holidays.

Health Secretary Matt Hancock stoked the rumours earlier today when he said the Tier 3 restrictions were not enough to control the new variant.

“This new variant is much easier to catch, it is much more transmissible, and we’re now seeing the effect of that in lots of different parts of the country, unfortunately."

He told Sky News: “We don’t rule anything out, and we’ve shown repeatedly that we will look at the public health advice and we will take the public health advice in terms of what is needed to control the spread of the disease.

“This new variant is much easier to catch, it is much more transmissible, and we’re now seeing the effect of that in lots of different parts of the country, unfortunately.

“And it means that, whereas the old Tier 3 was able to contain the old variant, that is proving increasingly difficult in all parts of the country.”

Kent was already in the highest tier restrictions after a new variant emerged in the county.

On December 19, all non-essential retailers, hairdressers and gyms had to close under the Tier 4 rules. It was a real blow to business owners who had worked hard to be able to work in a safe way.

Analysis of the lockdown announcement by KM political editor Paul Francis

Schools to shut, exams cancelled, sports fixtures ending, an NHS buckling under the strain, an order to stay at home, non-essential shops to close.

The Prime Minister’s address announcing a third national lockdown was about as stark as it could be.

Much of it was already heavily trailed but even so, it was a sobering assessment of just how serious a situation the country faces.

The most startling figure was that hospital admissions now are 40% higher than they were at the peak in the first lockdown, a graphic illustration of just how close the NHS is to being overwhelmed.

If the new lockdown is all but identical to the first, there was this time something to sugar the pill, namely that we do now have vaccines available which were not around last March.

But even that came with qualifications and a note of caution.

If we succeed in vaccinating all those groups “we will have removed huge numbers of people from the path of the virus," he said.

"That will eventually enable us to lift many of the restrictions we have endured for so long."

The address ended with a contention that if the restrictions were observed and “everyone played their part” the lockdown could begin to be eased by mid-February.

It was, he said, a pivotal moment in halting the march of the virus.

Time will tell.

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