Prime minister Boris Johnson announced that the UK would enter a "tough" new national lockdown to control the spread of the new Covid variant.
In an address to the nation he said this meant "the Government is once again instructing you to stay at home."
People are allowed to leave home only for reasons permitted by law. These include shopping for essentials, seeking medical assistance and escaping domestic abuse.
The prime minister also said people were able to leave home to go to work "if you absolutely cannot work from home".
So, who should still be going to work?
According to information published online by the Cabinet Office those who should still be going into work include: "people who work in critical national infrastructure, construction, or manufacturing.
"Public sector employees working in essential services, including childcare or education, should continue to go into work.
The regulations also state that people should avoid meeting for work in a "private home or garden, where Covid-19 secure measures may not be in place".
Work meetings can, however, take place in public outdoor spaces like parks.
People whose work makes it necessary for them to be in people's houses — such as "nannies, cleaners or tradespeople" — can continue to work.
Can I still stay away from home for work?
During the third coronavirus lockdown people who "require accommodation for work purposes" are still allowed to stay away from home overnight.
What if I am particularly at risk to coronavirus?
In his address to the nation, the prime minister said: "If you are clinically extremely vulnerable, we are advising you to begin shielding again and you will shortly receive a letter about what this means for you."
The Cabinet office documents say that people who are "clinically extremely vulnerable should not attend work, school, college or university, and limit the time you spend outside the home".
What should my work provide for me if I am working from home?
The government says employers should "take every possible step to facilitate their employees working from home, including providing suitable IT and equipment to enable remote working".
Tracey Munro, HR consultant at East Anglian firm, Mad-HR, said employees may need to be with office equipment and furniture in order to work from home.
These could include a desk or table and an office chair or even a computer.
She said: "Ideally, laptops should be supplied rather than desktop computers as these are easier for manual handling purposes.
"If the employee is required to access the work network remotely, the employer should check that the employee already has an internet connection which is suitable.
"If not, then they may need to look at hotspot connection via a mobile phone. Where the employee does not have a company mobile, the employer should look to reimburse the employee for any out of pocket costs associated with data-usage on personal mobile phones."
What are my rights if I have to home school my children and work at the same time?
Schools across England have closed for all pupils except vulnerable children and the children of critical workers until February half-term.
All other children will learn remotely until then.
This means many parents will now be working from home and home-schooling their children at the same time.
Ms Munro said that employers and employees should discuss "reasonable adjustments" that may need to be made to accommodate this.
She added: "If necessary, a short-term variation to contract may need to be agreed if working hours need to be reduced to allow for childcare arrangements.
"Ultimately it is about having a conversation with the individual and considering what options there are available to achieve the desired outcome.
"As long as the work is done and the deadlines are met, is it critical if it is achieved between 9-5 or can they work in the evening once the children have gone to bed? Adopting a flexible arrangement that suits both the individual and the business is surely a win win."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here