More than a quarter of the UK population is set to be under coronavirus lockdown rules, as new measures come into force this weekend.
From Saturday in England, households in Leeds, Wigan, Stockport and Blackpool will be banned from mixing in each other’s homes or gardens.
In Wales, Llanelli will be subject to new rules from 18:00 BST, with Cardiff and Swansea following 24 hours later.
It comes as the rate at which the virus is spreading appears to be speeding up.
The R number - which indicates how many people someone with coronavirus infects - has risen in the last week and now stands at 1.2 to 1.5. A number above 1 means the virus is spreading within the community.
Meanwhile, the daily number of confirmed Covid-19 cases in the UK reached a record high of 6,874, government figures on Friday showed.
In England, the “rule of six” and a 22:00 closing time for pubs and restaurants applies nationally.
But extra restrictions are also in place in large parts of north-east and north-west England, West Yorkshire and the Midlands where the infection rate is higher.
The latest rules for Leeds, Wigan, Stockport and Blackpool came into force at midnight and ban different households from mixing inside private homes or gardens.
Support bubbles are not affected and friends and family can still provide informal childcare for children under 14.
People are also advised not to socialise with people they do not live with in any other settings, including bars, shops and parks.
Later on Saturday, Wales - where the R number is between 0.7 and 1.2 - will see its first town-only lockdown, with people in Llanelli in Carmarthenshire banned from leaving town or mixing indoors with anyone outside of their household.
The same rules will then be brought in for Wales’ two biggest cities - Cardiff and Swansea - at 18:00 on Sunday. People will not be able to enter or leave the areas without a reasonable excuse, the Welsh Government has said.
It means by the end of the weekend, about half of Wales’ population will be under lockdown - 1.5 million people.
And the total number of people across the UK living under stricter rules will stand at 17 million.
Health Secretary Matt Hancock said he recognised “the burden and impact these additional measures have on our daily lives but we must act collectively and quickly to bring down infections”.
It comes as London was added to the government’s Covid-19 watch-list - with all boroughs classed as areas of concern.
Meanwhile, up to 1,700 students at Manchester Metropolitan University have been told to self-isolate for two weeks in their student halls, after a spate of positive tests for Covid-19.
Students said they saw security and police officers outside their accommodation and were “told we are not allowed to leave”.
And students in Scotland have been told not to socialise with anyone outside of their accommodation or go to pubs, parties or restaurants this weekend in a bid to stop outbreaks.
In other developments:
- The UK is to give £500m to a new global vaccine-sharing scheme designed to ensure treatments for Covid-19 are distributed fairly
- Demand for coronavirus tests has almost trebled among young children in England this month - but only 1% were found to have the virus, figures show
- The World Health Organization has warned that a global coronavirus death toll could hit two million before an effective vaccine is widely used
- Fewer than 0.1% of people stopped by police for not wearing masks on trains received a fine, figures have revealed.