London CNN  — 

UK Prime Minister Boris Johnson held an emergency meeting with ministers on Monday, after fears about a new coronavirus variant discovered in the country prompted a chaotic border shutdown and saw British travelers shut out from dozens of countries in Europe and around the world.

Alarm over the new variant, which was first identified in England, led a number of nations to impose restrictions on travel from the UK.

France announced a temporary ban on all travel and accompanied freight on Sunday night, a potential disaster for UK exporters who rely on trade with Europe. The border closure exacerbated pre-Christmas delays, with trucks backed up from the port of Dover in the southeast of England, a key crossing point for hauliers.

Worse, the move has sparked worry that European exporters would be reluctant to send goods to the UK, for fear of not being able to return. The timing of the restrictions, just days before Christmas and the end of the Brexit transition period, raised concerns about food and medicine shortages in the UK at a critical time.

Johnson sought to allay those concerns in a televised press conference on Monday, telling Britons that “the vast majority of food and medicine supplies are coming and going as normal.”

His transport secretary, Grant Shapps, added that 170 lorries were still stuck on the motorways around Dover, with more in a holding area, but said that number had been reduced from over 500 on Sunday night.

It came after Kent Police were forced to close sections of England’s M20 motorway to “avoid gridlock” in the area surrounding the Eurotunnel. Operation Stack – a contingency plan that allows part of the highway to be allocated to parked trucks – has been put in place.

Trucks parked on the M20 near Folkestone, Kent, as part of Operation Stack after the Port of Dover was closed and access to the Eurotunnel terminal suspended.

France said it was working to bring in a European-wide health protocol that would allow freight to start flowing again.

“In the next few hours, at the European level, we are going to put in place a solid health protocol so that flows from the United Kingdom can resume,” Secretary of State for Transport Jean-Baptiste Djebbari tweeted Monday. “Our priority is to protect our nationals and our citizens,” he added.

Johnson said he had spoken with French President Emmanuel Macron on Monday and insisted that the risk of transmission from a solitary truck driver was low.

Representatives of the road haulage industry called on the UK government to deploy rapid testing for truck drivers to restore confidence in the French authorities that they are Covid-free.

“Right now there will be concern around a backup if this persists for longer than 48 hours because eventually there will be a position where the delays on the exit journey will be quite substantial,” said Alex Veitch, general policy manager for Logistics UK, on BBC Radio 4.

British supermarkets said that warehouses were well stocked at present. Sainsbury’s warned that shortages of perishable goods could start to appear in the coming days, if the situation is not resolved quickly. A Sainsbury’s spokesperson told the PA Media news agency: “All products for the Great British Christmas lunch are already in the country and we have plenty of these. If nothing changes, we will start to see gaps over the coming days on lettuce, some salad leaves, cauliflowers, broccoli and citrus fruit – all of which are imported from the continent at this time of year.”

Travel restrictions

By Monday, dozens of countries across Europe, the Middle East and the Americas had announced travel bans for the UK. Others, such as Greece and Spain, have imposed restrictions that require travelers arriving from Britain to undergo coronavirus tests or quarantine.

Canada announced a travel ban from midnight Sunday for at least 72 hours. In a