The Prime Minister will host a cabinet call “shortly” and will later hold a press conference with the chief medical officer Chris Whitty and the chief scientific adviser Sir Patrick Vallance, Downing Street has said.

It comes following pressure on the Prime Minister to up the Covid restrictions in light of the new variant spreads. 

The Prime Minister’s press conference will take place at 4pm, Downing Street said.

READ MORE: Boris Johnson coronavirus briefing: What time is it at and how can I watch?

According to reports, the prime minister is expected to announce a tightening of Covid restrictions and a tier four for London and the South East as well as several other counties.

Plans to relax the rules around households gathering during the Christmas period may also be tightened.

READ MORE: Nicola Sturgeon warns 'preventative action may be necessary' amid fears of new variant Covid

Professor Chris Whitty, chief medical officer for England, said the UK has informed the World Health Organisation that the new variant coronavirus can spread more rapidly.

“As announced on Monday, the UK has identified a new variant of Covid-19 through Public Health England’s genomic surveillance,” he said in a statement.

“As a result of the rapid spread of the new variant, preliminary modelling data and rapidly rising incidence rates in the South East, the New and Emerging Respiratory Virus Threats Advisory Group (NERVTAG) now consider that the new strain can spread more quickly.

“We have alerted the World Health Organisation and are continuing to analyse the available data to improve our understanding.

“There is no current evidence to suggest the new strain causes a higher mortality rate or that it affects vaccines and treatments, although urgent work is under way to confirm this.

“Given this latest development, it is now more vital than ever that the public continue to take action in their area to reduce transmission.”

Shadow health secretary Jonathan Ashworth has called on Boris Johnson to set out how he intends to stem the spread of coronavirus in an address to the nation.

READ MORE: VUI: Everything you need to know about the new Covid strain

“It has been apparent for some days that the virus is again out of control in parts of the country. The Government’s tiered system has failed to stem its spread,” he said in a statement.

“This is an incredibly serious moment and people are worried. The Prime Minister has refused to take action to limit the virus’ spread over Christmas. All he has offered so far is confusion and indecision.

“He must now address the nation to explain what action he will be taking.”

Professor Sir Mark Walport – a Sage member and a former chief scientific adviser to the Government – said there was a real possibility the new variant could have a “transmission advantage” enabling it to spread more rapidly.

He warned the country was heading into the new year in a “serious situation”.