LauraNorder
If we had reason to close our borders we would repatriate our nationals ASAP and meanwhile ensure they were fed. We have been shown to do this many times, eg planes provided for stranded holidaymakers throughout the world when covid kicked off.
This variant and others are already in mainland Europe. The lorries could be allowed to cross the channels and undergo testing and quarantine in their home country. This would be less chaotic all round.
I’m sure the EU could fly their citizens home but I’m not sure what would happen to the lorries



