Prime Minister Boris Johnson says the national lockdown will start in England on Thursday.
The lockdown is expected to last for four weeks.
The new restrictions mean people will only be allowed to leave their homes for specific reasons – food shopping, exercise, education and work.
A household will be banned from mixing, but support bubbles and childcare bubbles will remain.
Children whose parents are separated will still be allowed to move between homes.
Pubs, restaurants and bars will close, however, they can still operate takeaway services.
The PM said non-essential shops will be forced to shut but schools, colleges, and universities will remain open.
Vulnerable people won’t be asked to shield again but will be guided to minimize contacts as possible as they can.
The new restrictions do not affect playgrounds as it will be expected to open, no bans on a picnic or sitting on park benches for long, or individual meeting another individual from another household.
The lockdown which starts on Thursday will end on 2 December, when the country will be expected to return to system based – tier system.
Mr Johnson said, “From Thursday, the basic message is the same – stay at home, protect the NHS and save lives.”
The PM says there is no “alternative” to return to a “stay at home” message, contrary to statement credited to senior cabinet ministers as recently as yesterday, insistent there was an alternative and that the targeted regional measures were better than the proposed national lockdown.
When asked by Sky News political Editor Beth Rigby if the PM regretted not following the scientific advice more closely, Mr Johnson said, “We have to listen to all kinds of scientific advice… but we also have to balance that scientific advice with the consequences for people’s lives.”
“There’s a range of advice and a balance we have to strike.”
He adds: “I’m not going to pretend to you these judgments aren’t incredibly difficult. We have to change with the changing pattern of the virus.”
Asked whether it is now too little too late to get us to a place where we will be able to celebrate Christmas with our families, Professor Whitty says “there is no perfect time and there are no good solutions”.
“We would have a much better chance of doing it with these measures than if these measures weren’t taken today.”