Watch: North East lockdown begins as curfew for bars and pubs and ban on household mixing brought in
The Government is reportedly planning to enforce a ban on socialising and household mixing across London and much of northern England to help curb the spread of coronavirus.
Under the new emergency lockdown, all bars, restaurants and pubs would be told to shut for two weeks initially, while households would be banned indefinitely from meeting indoors, the Times reports.
As part of the social lockdown, ministers reportedly said schools, offices, and shops would stay open.
The option is said to have been presented to the Cabinet's Covid-19 strategy committee last week, before new restrictions, including a 10pm curfew on all hospitality venues, came into force.
A Government source told the newspaper: "The nation and the party wasn’t ready for us to go any further last week. There wasn’t a wide enough understanding of how substantial the second wave could be.
"Tougher measures on social interaction will have to come though. They’re inevitable in some parts if you look at the numbers."
It comes as new local lockdowns, further restrictions and tough new fines for failing to self-isolate come into force across parts of the UK on Monday.
People across England will be legally required to self-isolate from this week if they test positive for coronavirus or are contacted by the test and trace service.
If they do not they risk being hit with new fines starting at £1,000 and increasing up to £10,000 for repeat offenders or serious breaches, the Department of Health and Social Care said.
People who test positive for Covid-19 will also be fined if they knowingly provide false information about close contacts to the test and trace service.
Under new rules in England wedding ceremonies will also be restricted to 15 people.
Meanwhile three more council areas in South Wales will go into local lockdown from 6pm on Monday, the Welsh Government has announced.
Watch: What are the fines for breaching self-isolation? Find out here
Neath Port Talbot, Torfaen and the Vale of Glamorgan will be covered by the restrictions, which mean people will not be able to enter or leave the areas without a reasonable excuse.
It comes after bans on households mixing came into force in Wigan, Stockport, Blackpool and Leeds on Saturday, while stricter rules are already in force across large swathes of north-west England, West Yorkshire, the North East and the Midlands, as well as parts of west Scotland.
The Government said that, as of 9am on Sunday, there had been a further 5,693 lab-confirmed cases of coronavirus in the UK.
A further 17 people had died within 28 days of testing positive for Covid-19 as of Sunday.
Health Secretary Matt Hancock said the Government will “not hesitate” to introduce further measures if case numbers continue to rise.
"Anyone can catch coronavirus and anyone can spread it," he said.
"We all have a crucial part to play in keeping the number of new infections down and protecting our loved ones.
"As cases rise it is imperative we take action, and we are introducing a legal duty to self-isolate when told to do so, with fines for breaches and a new £500 support payment for those on lower incomes who can’t work from home while they are self-isolating.
“These simple steps can make a huge difference to reduce the spread of the virus, but we will not hesitate to put in place further measures if cases continue to rise."
But ministers are also under growing pressure to review the "hard" 10pm curfew on pubs, bars and restaurants amid criticism that the new rules are leading to revellers filling streets en masse.
Crowds of people were pictured on Saturday night gathering in city centres and piling onto public transport, while long queues formed at off licences after venues kicked customers out at 10pm.
But Culture Secretary Oliver Dowden insisted on Sunday that there was "definitely science" behind the curfew, despite a scientist advising the Government saying he had "never heard" the measure discussed at Sage meetings.
Mr Dowden also said that university students should be able to return home to their families at Christmas if the country "pulls together" and observes the new coronavirus rules.
The Government is under pressure to guarantee young people are not confined to their halls of residence over the festive period because of Covid-19 outbreaks on campuses.
Thousands of students are currently self-isolating in their rooms following a surge in cases at institutions including Glasgow, Manchester Metropolitan and Edinburgh Napier.
Students in Scotland have been told they can return home from university accommodation on a long-term basis, as long as they follow rules on self-isolating.