Finance minister Rishi Sunak announced a new package of business grants worth 4.6 billion pounds ($6.2 billion) to help keep people in jobs and firms afloat until measures are relaxed gradually, at the earliest from mid-February but likely later.

Britain has been among the countries worst-hit by COVID-19, with the second highest death toll in Europe and an economy that suffered the sharpest contraction of any in the Group of Seven during the first wave of infections last spring.

Prime Minister Boris Johnson announced the new lockdown late on Monday, saying the highly contagious new coronavirus variant first identified in Britain was spreading so fast the National Health Service risked being overwhelmed within 21 days.

In England alone, some 27,000 people are in hospital with COVID, 40% more than during the first peak in April.

"The weeks ahead will be the hardest yet but I really do believe that we are entering the last phase of the struggle, because with every jab that goes into our arms, we are tilting the odds against COVID and in favor of the British people," said Johnson.

Britain has begun rolling out two vaccines, one made by Pfizer and BioNTech and the other by Oxford University and AstraZeneca, and more than a million people have already received their first dose.

Since the start of the pandemic, more than 75,000 people have died in the United Kingdom within 28 days of testing positive for coronavirus, according to official figures.

Under the new lockdown in England, schools are closed to most pupils, people should work from home if possible, and all hospitality and non-essential shops are closed.

The semi-autonomous executives in Scotland, Wales and Northern Ireland have imposed similar measures.

Sunak's latest economic package adds to the eye-watering 280 billion pounds in government support already announced for this financial year to stave off total economic collapse.

"This will help businesses to get through the months ahead - and crucially it will help sustain jobs, so workers can be ready to return when they are able to reopen," he said in a statement.

The government aims to vaccinate all elderly care home residents and their carers, everyone over the age of 70, all frontline health and social care workers, and everyone who is clinically extremely vulnerable, by mid-February.

Senior minister Michael Gove said the pace of inoculations would accelerate in the coming weeks, but struck a cautious tone about when that might translate into an easing of restrictions.

"We'll be able to review the progress that we've made on Feb.15 ... and we hope that we'll be able to progressively lift restrictions after that, but what I can't do is predict, nobody can predict with accuracy what we will be able to relax and when," he said on Sky News.

Gove also said the government would soon announce new measures aimed at international travelers.

"There are some journeys that do need to be made for vital commercial reasons - to make sure that we've got drugs in our hospitals, food on our shelves and so on - so it's not as simple as a blanket restriction," Gove said on LBC radio.

"What it is, is making sure that we have the safest possible approach and that involves reviewing how ports and airports work."