In an emergency press conference yesterday Boris Johnson announced that London, the south and the south-east of England would be going into a tier four lockdown from today.

Supermarkets have urged shoppers not to panic buy as they expect people, who were previously relying on relatives or friends, to rush to buy Christmas groceries.

With less than a weeks’ notice, millions of people have been forced to rethink their Christmas dinner plans without guests to cook for.

So Brits are now using the last weekend before Christmas to reshuffle their arrangements, shop and prepare – all while a new mutant strain of Covid spreads across the country.

A source for Tesco told the Telegraph: ‘We will not run out of food. There is no reason to panic buy.

‘There are the same number of shoppers out there as there were before any new announcement and we have enough stock to supply them all, even if more now come into our stores because online delivery slots are full.’

Londoners were seen waiting in huge queues outside Tesco, while long lines of shoppers snaked outside other supermarkets, including Marks and Spencer.

After Bedfordshire went into tier four Northamptonshire’s Rushden Lakes shopping centre, which is in tier two, was packed with visitors.

The centre is in East Northamptonshire – only about a mile away from Bedfordshire which is not allowed to have any non-essential shops open.

The car park was packed full this morning

Rushden Lakes shopping centre, in Nothamptonshire, was packed with visitors after Bedfordshire, about a mile away, went into tier four

The scenes outside supermarkets today comes after thousands of people swarmed to shops last night before non-essential retail was forced to close.

People used the last few hours to do whatever Christmas shopping they could, with stores remaining closed until at least December 30 when the government is set to review the tiers.

Shoppers flocked to Oxford Street making social distancing practically impossible.

Windsor’s town-centre was busy today despite being plunged into tier four at midnight

Social media was flooded with posts warning people to stay away from Bluewater shopping complex in Kent with photographs and videos showing cars queuing for miles along the A2.

A sales assistant at a department store at Westfield shopping centre in West London said: ‘It was fairly quiet all day, then suddenly there was this mass of people.’

Someone else tweeted that Westfield in Stratford was a ‘zoo not a shopping mall’.

The whole of Wales also went into tier four at midnight leaving shoppers a few hours to rush to Cardiff city-centre before the lockdown.

There were similar scenes in Cardiff city-centre as Wales also went into tier four

Similarly, the last-minute news sent Londoners packing intro train stations to try to get home before the stay-at-home order came into force.

People crammed into St Pancras and Paddington getting trains to Leeds and other parts of the country to be with their families over Christmas.

Matt Hancock today slammed Londoners for gathering at train stations last night and called them ‘totally irresponsible’.

Londoners fleeing city 'totally irresponsible' says Health Secretary

He told Sky News: ‘This was clearly totally irresponsible behaviour. The Chief Medical Officer (Professor Chris Whitty) was absolutely clear that people should unpack their bags if they have them packed.

‘I think it is relatively small numbers and the large, vast majority of people throughout this whole pandemic have followed the rules, been responsible and played their part and I want to thank everybody for doing that.

‘It is more important than ever that people are responsible, not only stick to the rules, but even within the rules restrict social contact as much as is possible because this is deadly serious.’