Clinically extremely vulnerable people in tier 4 areas are being told not to go to work even if they are unable to work from home in new guidance published on shielding.
People across London, the South East and the East of England received further guidance online on Monday after the areas moved into Tier 4 restrictions over the weekend.
Those who are at very high risk of severe illness from coronavirus, including people with specific cancers and severe respiratory conditions, are being urged to stay at home and only leave to exercise or attend health appointments.
People who cannot work from home are being told they should not attend work, while children on the shielded patient list should not attend school during term times.
They are advised to avoid all non-essential travel unless they are heading to hospital and GP appointments, and to avoid going into any shops and pharmacies.
The guidance states people who live with someone who is clinically extremely vulnerable, but are not themselves, should still attend work and school.
The updated guidance follows the same rules that were in place during the second national lockdown in England during November.
The government said those who are clinically extremely vulnerable but living in Tiers 1 to 3 should follow existing guidance, and that there is no formal shielding advice currently in place in areas outside of Tier 4.
Letters are being sent out to all those affected by the new rules later this week, although they will be delayed due to the Christmas period.