EU countries have been told to lift their travel bans on the UK to allow essential journeys and minimise trade disruption.
Dozens of countries have blocked people arriving from Britain over fears about the new coronavirus variant that is said to be much more transmittable.
France has gone a step further by stopping lorry drivers crossing the Channel, creating chaos on the approach to Dover.
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Following talks, the EU Commission said in a statement it was “important to take swift temporary precautionary action” to limit the spread of COVID-19.
But added: “Flight and train bans should be discontinued given the need to ensure essential travel and avoid supply chain disruptions.”
The EU commissioner for justice, Didier Reynders, added that “blanket travel bans should not prevent thousands of EU and UK citizens from returning to their homes” in the run up to Christmas.
Within hours, Ireland announced it would defy the directive and keep up its travel ban on Britain until 31 December.
Germany was also considering extending its ban on travellers arriving from the UK to 6 January, with exceptions for German nationals or residents from 1 January, Reuters reported earlier.
Separate bilateral negotiations are ongoing in a bid to restart travel to France, given the big backlog of lorries piling up in Kent waiting to board trains and ferries to cross the Channel.
Sky News understands a deal could be struck today and see rapid-turnaround lateral flow tests being conducted on lorry drivers with the help of the military.
The coronavirus variation that has wreaked havoc is known as VUI-202012/01. It was found predominantly in London and southeast England.
But it has also been discovered in every region of England, Wales and Scotland, albeit in “very small numbers”.
Similar strains have been detected in Denmark and Australia, and there are other variants that look very similar detected in South Africa, the Netherlands and other countries, said Dr Susan Hopkins of Public Health England.
Ireland will introduce stricter restrictions from Christmas Eve because of fears the new variant is spreading there, Prime Minister Micheal Martin announced on Tuesday.
“We do not yet have evidence that the new, more virulent strain of the virus is in our country, but the rate of growth over the last week tells me that the safest, most responsible thing to do is to proceed on the assumption that it is already here,” he said.
But the boss of BioNTech, one of the firms behind the only coronavirus vaccine approved for use in the UK, said earlier he is confident the jab will be effective against the new variant.
Around 500,000 people in the UK have had the first shot of immunisation, but England could face another effective lockdown in the new year while roll-out continues.
Prime Minister Boris Johnson has voiced hopes life will return to normal by Easter, marking a year since the first lockdown.
Since the pandemic began, 76,287 people in the UK have died with COVID-19 on their death certificates – one of the highest death tolls in the world.