Updated guidance has been issued to vulnerable residents who live in areas that come under the UK Government's toughest Tier Four restrictions in England.
A new letter, sent to those living under the strict measures, advises people not to go to work if there are unable to do their jobs from home and tells them not to leave their house "as much as possible".
The guidelines come after Boris Johnson placed millions of people into Tier Four just before Christmas with more places possibly joining London and the South East in the coming days, BirminghamLive reports.
Latest tier changes are expected to be announced on Wednesday following the emergence of a new variant of the virus, which has seen cases rocket across London boroughs.
The letter reads: "We are writing to you because you have previously been identified as someone thought to be clinically extremely vulnerable and at highest risk of becoming very unwell if you catch Covid-19.
The advice states that you should stay at home as much as possible but are encouraged to go outdoors carefully to exercise or to attend health appointments.
"You are strongly advised to work from home if you can. If you cannot work from home, then you should not attend work.
"You may be eligible for the Coronavirus Job Retention Scheme (furlough). This letter is a formal shielding notification and can act as evidence for your employer to show that you cannot work outside your home until 18 January 2021, including for statutory sick pay (SSP) purposes.
"This advice will apply in your area until 18 January 2021, even if your area is placed in a different tier before then. If the advice is to continue beyond that date, we will write to you again with further information."
There is continuing discussion about how the new strain of coronavirus will affect schools returning in the New Year with some establishments tasked to supply coronavirus testing for pupils next month.
