“Good afternoon,

I am sorry to report that the situation has deteriorated since I last spoke to you three days ago.

Yesterday afternoon, I was briefed on the latest data showing the virus spreading more rapidly in London, the South East and the East of England than would be expected given the tough restrictions which are already in place.

I also received an explanation for why the virus is spreading more rapidly in these areas. It appears this spread is now being driven by the new variant of the virus, which we first learned about earlier this week.

Our advisory group on New and Emerging Respiratory Virus Threats – NERVTAG – has spent the last few days analysing the new variant.

There is no evidence the variant causes more severe illness or higher mortality, but it does appear to be passed on significantly more easily.

NERVTAG’s early analysis suggests the new variant could increase R by 0.4 or greater. Although there is considerable uncertainty, it may be up to 70% more transmissible than the old variant.

This is early data. It is subject to review. It is the best we have at the moment, and we have to act on information as we have it because this is now spreading very fast.

The U.K. has by far the best genomic sequencing ability in the world, which means we are better able to identify new strains like this than any other country.

The Chief Medical Officer last night submitted our findings so far to the World Health Organisation and we will continue to be totally transparent with our global partners.

There is still much we don’t know. While we are fairly certain the variant is transmitted more quickly, there is no evidence to suggest that it is more lethal or causes more severe illness. Equally there is no evidence to suggest the vaccine will be any less effective against the new variant.

Our experts will continue their work to improve our understanding of the variant.

So we are learning more about this variant as we go.

But we know enough already to be sure that we must act now.

I met ministers on the Covid Operations Committee last night and again first thing this morning, and 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, indoor gyms and leisure facilities, and personal care services must close. People must work from home if they can, but may travel to work if this is not possible, for example in the construction and manufacturing sectors. 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 public space.

Unlike the November national restrictions, communal worship can continue to take place in tier 4 areas.

These measures will take effect from tomorrow morning.

All tiers will continue to be regularly reviewed in line with the approach previously set out, with the next formal review point taking place on 30 December.

Second, we are issuing new advice on travel.

Although the new variant is concentrated in tier 4 areas, it is nonetheless present at lower levels around the country.

We are asking everyone, in all tiers, to stay local.

People should carefully consider whether they need to travel abroad and follow the rules in their tier.

Those in tier 4 areas will not be permitted to travel abroad apart from limited exceptions, such as for work purposes.

Third, we must, I am afraid, look again at Christmas.

As Prime Minister, it is my duty to take the 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, and the potential risk it poses, it is with a heavy heart that I must tell you 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.

Across the rest of the country, the Christmas rules allowing up to three households to meet will now be limited to Christmas Day only, rather than the five days as previously set out.

As before, there will be no relaxation on 31 December, so people must not break the rules at New Year.

I know how much emotion people invest in this time of year, and how important it is for grandparents to see their grandchildren, and for families to be together.

So I know how disappointing this will be, but we have said throughout this pandemic that we must and we will be guided by the science.

When the science changes, we must change our response.

When the virus changes its method of attack, we must change our method of defence.

As your Prime Minister, I sincerely believe there is no alternative open to me. Without action, the evidence suggests infections would soar, hospitals would become overwhelmed and many thousands more would lose their lives.

I want to stress we are not alone in this fight – many of our European friends and neighbours are being forced to take similar action.

We are working closely with the devolved administrations to protect people in every part of the UK.

Of course there is now hope – real hope – that we will soon be rid of this virus.

That prospect is growing with every day that passes and every vaccine dose administered.

The UK was the first country in the western world to start using a clinically approve vaccine.

So please, if the NHS contacts you then get your vaccine – and join the 350,000 people across the UK who have already had their first dose.

Yes, Christmas this year will be very different, but we must be realistic.

We are sacrificing our chance to see loved ones this Christmas, so we have a better chance of protecting their lives so we can see them at future Christmases.

As sure as night follows day, we will beat back this virus.

We will defeat it.

And we will reclaim our lives.”