Christmas plans will be cancelled after the Prime Minister plunged Kent into even tighter Covid-19 restrictions.

Speaking from Downing Street this afternoon, Boris Johnson confirmed the stricter Tier 4 measures for the county amid growing concern over a new, fast-spreading strain of the coronavirus now circulating in the south east of England.

The Cabinet met this lunchtime to discuss the mutation of the virus and the troubling increase in infection rates, both in Kent and beyond, just days before the previously expected easing of restrictions for the Christmas holidays.

Mr Johnson had long wished to avoid dashing people's hopes of family gatherings during the festive season, but his hand has been forced by spiralling case rates and the emergence of the new strain of the virus.

However this afternoon he confirmed that household mixing at Christmas will now be off the agenda for Kent -where 51 Covid-19 deaths were reported today - and other parts of the country worst-hit by the virus.

He said: "Cabinet met at lunchtime to agree the following actions. First, we will introduce new restrictions in the most affected areas, specifically those parts of London, the south east and the east of England, which are currently in Tier 3.

"These areas will enter a new Tier 4 which will be broadly equivalent to the national restrictions which were in place in England in November. That means residents in those areas must stay at home, apart from limited exemptions set out in law, non-essential retail, gyms and leisure facilities, and personal care services must close, people must work from home where they can.

"People should not enter or leave Tier 4 areas, and Tier 4 residents must not stay overnight away from home. Individuals can only meet one person from another household in an outdoor space."

Addressing the issue of the forthcoming festivities, Mr Johnson said: "We must, I'm afraid, look again at Christmas.

"As Prime Minister it is my duty to take difficult decisions, to do what is right to protect the people of this country. Given the early evidence we have on this new variant of the virus, the potential risk that it poses, it is with a very heavy heart that I must tell you that we cannot continue with Christmas as planned.

"In England, those living in Tier 4 areas, should not mix with anyone outside their own household at Christmas, though support bubbles will remain in place for those at particular risk of loneliness or isolation."

Earlier England’s Chief Medical Officer, Chris Whitty, confirmed the newly-identified mutation of the virus does appear to be spreading faster that previous strains, and work is ongoing to assess its danger to those infected.

He said: "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 underway 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."

Latest figures published by Kent County Council show there are currently 597 weekly cases per 100,000 people across the county, with Swale the worst-affected area with a rate of 792.9.

The national rate for England currently stands at 251.2.

Read more: All the latest news from Kent