Boris Johnson has announced details of a new national lockdown for people in England, which will begin on Thursday and last until December 2.
"Now is the time to take action because there is no alternative," the Prime Minister said in a Downing Street press conference.
Pubs, bars and restaurants will close, though takeaways will be allowed to stay open, and all non-essential retail will be shut.
Schools and universities will be kept open throughout this new measure, unlike in the lockdown earlier this year.
The PM also announced that the furlough system, which was due to come to an end, will be extended throughout November.
MPs will vote on the new measures before they are introduced at 00.01 on Thursday, and when they lapse, the current tier system will be reintroduced.
The key points for England in full
From Thursday, November 5 until Wednesday, December 2:
You must stay at homeThe only permitted reasons for leaving home will be: for education, for work, if you cannot work from home, for exercise and recreation outdoors, for medical reasons, to shop for food and essentials, to care for others.Non-essential shops will close.Schools and universities will remain open.Pubs, bars and restaurants will close, but takeaways will be allowed to stay open.Support bubbles will still be allowed and children can move homes if their parents are separated.
Mr Johnson warned that "the virus is spreading even faster than the worst case scenario of our scientific advisors".
However, he claimed that the regional tier approach he announced two weeks ago was the "right thing to do" at the time.
Acknowledging that Christmas was going to be different this year, the PM said that by following these measures "we can allow families across the country to be together".
The introduction of national restrictions marks a dramatic shift in Government policy, as the Mr Johnson has until now resisted calls to reintroduce nationwide restrictions, despite mounting scientific and political pressure.
Chief Medical Officer Professor Chris Whitty told the press conference : “We now have several hospitals with more inpatients with Covid than we had during the peak in the spring.”
Prof Whitty added that “the death rate, although rising, is still significantly below the peak”.
But if numbers keep rising, “in terms of deaths over the winter, there’s the potential for this to be twice as bad, or more, compared to the first wave,” according to Chief Scientific Officer Sir Patrick Vallance.
The situation in Scotland, Wales and Northern Ireland
Scotland is due to move into a regional tier system on Monday (2 November) at 6am.
Earlier, Nicola Sturgeon told Scots not to travel to England unless it is for “essential purposes”. The Scottish First Minister said the prevalence of the virus is lower in Scotland than in other parts of the UK, after stricter measures were introduced north of the border in September.
Mark Drakeford, First Minister of Wales, reiterated that the firebreak lockdown in Wales, which came into force on October 23, will end on November 9. He said any announcement by Downing Street will “relate to England”.
Northern Ireland's First Minister Arlene Foster has said that the tighter restrictions there will end as planned on November 13.