Passenger flights and ferries from Britain to the Republic of Ireland have now stopped, after a temporary ban on travel come into effect at midnight.
The unprecedented 48-hour ban - which may be extended after Cabinet meets tomorrow - comes amid concern over a new strain of coronavirus which the British government says has spread rapidly in parts of England.
Only essential supply chain workers are now allowed travel here from Britain, and ferry crossings will continue to allow for necessary haulage.
The Department of Foreign Affairs is working to repatriate Irish residents who were on short trips there.
Meanwhile, EU member states will have an emergency meeting later to discuss the situation, as a growing list of European countries introduce travel restrictions for Britain.
British lorries have been temporarily banned from entering France.
The Port of Dover ferry terminal is now closed to all accompanied traffic leaving the UK until further notice. Operation Stack phase 2 has now been implemented.
— Port of Dover Travel (@PoD_travelnews) December 20, 2020
There were reports of crowding at some London airports as Irish and EU citizens attempted to return home before flights stopped at midnight.
In a statement, Aer Lingus said it will not operate any flights to Britain while the ban is in effect, but will operate flights to Britain for those with connecting flights or for British citizens who are being repatriated.
Travel update for the UK to Ireland ⬇️ pic.twitter.com/aZSVcVOeJp
— Aer Lingus (@AerLingus) December 20, 2020
Ryanair said any affected customers will be contacted by email and offered a free move to another flight or a refund.
Meanwhile, hundreds of people planning to sail from Britain to Ireland on overnight ferries were told to turn back last night
The last passengers and private cars allowed cross arrived in Dublin before the midnight deadline.
Stena Line is offering refunds to over 1,400 passengers who were booked to sail into Dublin and Rosslare today and tomorrow.
No decision was made by the Northern Ireland Executive last night on whether travel from Britain should be banned.
It's expected discussions between the parties will continue later today.