As part of the month-long lockdown, non-essential shops and hospitality businesses will have to close for a month.
But unlike the shutdown earlier this year, schools, colleges and universities will be allowed to stay open.
The lockdown starts at 12.01am on Thursday and lasts until December 2.
Under the new restrictions, the 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
Takeaways will be allowed to stay open but pubs, bars, restaurants, hairdressers and gyms will be among the places forced to close.
People will only be able to meet one person from outside their household in a public place outdoors.
Support bubbles will still be allowed and children can move homes if their parents are separated.
It comes as documents suggested the UK was now on course for a much higher death toll than during the first wave – and fears about the NHS being overwhelmed without action to tackle the spread of Covid-19.
Mr Johnson – who previously said ‘I don't want to get to a second national lockdown at all’ – led a news conference at Downing Street on Halloween.
He told the nation that the virus was spreading ‘even faster than the reasonable worst case scenario’ of scientific advisers.
“Now is the time to take action – there is no alternative,” Mr Johnson said.
“Stay at home, protect the NHS, save lives.”
He added: “It is my sincere hope that by taking this tough action now we can allow families to be together (for Christmas).”
He confirmed that the furlough scheme would be extended nationally until December.
The full regulations will be published on Tuesday and MPs will vote on them on Wednesday.
Gill Furniss, Labour MP for Brightside and Hillsborough, said the Government ‘needs to use the time to fix testing so it doesn’t keep repeating the same mistakes over and over again’.
Dan Jarvis, mayor of the Sheffield City Region and Labour MP for Barnsley, also called for the Test and Trace system to be ‘fixed’.
Toby Perkins, Labour MP for Chesterfield, said: “Two weeks ago, Labour leader Keir Starmer told the Prime Minister to accept the SAGE advice on a national lockdown before the half-term.
“Johnson’s failure to act cost hundreds of lives and thousands of infections and allowed the virus to spread.
“At every stage with this Government it’s too little, too late.”
Councillor Barry Lewis, leader of Conservative-run Derbyshire County Council, said: “If we have to have a four-week lockdown then let’s use that time to embed local track and trace and give local authorities the critical access to resources and proper test data.
“Let’s break the economically destructive lockdown cycle using local knowledge.
“Many ASEAN nations did it – we can too.”
Mr Johnson’s comments came after it emerged the number of confirmed coronavirus infections in the UK had passed one million.
A total of 46,555 people have died with the virus in the UK.
Covid-19 is a brief and mild disease for most people.