Health Secretary Sajid Javid is to make an urgent coronavirus announcement this morning.
The statement at 11am comes as a worrying new complex variant of Covid 19 has been discovered.
100 cases of the mutant variant have been found in three countries, prompting six nations to be added to the UK's red list for travel.
Mr Javid will speak in the House of Commons.
There are fears the virus will spread more easily and defeat vaccines as it has twice as many mutations as Delta - which could mean a return to restrictions in the UK.
Health Secretary Sajid Javid said the new variant identified in South Africa “may be more transmissible” than the Delta strain and “the vaccines that we currently have may be less effective”.
He said that flights to England from South Africa, Namibia, Lesotho, Botswana, Eswatini and Zimbabwe will be suspended from midday on Friday and all six countries will be added to the red list.
While no cases have been found in Britain, officials raised concern over a rapid rise in cases in South Africa.
Anyone who has arrived from the country in the last 10 days will be invited to come forward and take a test by the UK Health Security Agency.
The UK Government said on Thursday that UK and Irish residents who arrive in England between midday on Friday and 4am on Sunday, and who have been in the six countries within the last 10 days, must quarantine at home for 10 days and take NHS PCR tests on day two and day eight, even if they already have a lateral flow test booked.
Passengers – including UK and Irish residents – arriving from 4am on Sunday will be required to book and pay for a Government-approved hotel and quarantine for 10 days. They must also take tests on day two and day eight.
