Frustrated British travellers are scrambling from Portugal to the UK to avoid 10-day home quarantine after the country moves to the amber list.
Britain said last week it was removing Portugal from its green list of countries that do not require quarantine on return because of rising Covid-19 cases and the risk posed by coronavirus variants detected in Portugal.
The southern European country had been placed on the green list just weeks earlier, but from 4am UK time on Tuesday it will shift to the amber, meaning returning travellers will need to quarantine for 10 days and take several Covid-19 tests.
Portuguese Prime Minister Antonio Costa said Britain's traffic-light system was confusing and causing instability for the travel sector.
"We can't have this system of instability and changes every three weeks," he said.
"It isn't good for those who plan their holidays, nor for those who have to organise the tourism industry to receive tourists in good conditions."
Mr Costa said "a good way for the British to find a solution to this situation" would be to adhere to a system of digital certificates which the EU plans to introduce from July 1.
Under this scheme, EU citizens who can prove they have been vaccinated against Covid-19, tested negative for the disease or recovered from it will be able to travel freely in the EU.
Britain, however, has left the EU. Mr Costa did not explain how it might adhere to the scheme.
Queuing for a British Airways flight to London, Bryan Kelly said he had brought his family's return home forward from Wednesday because they would not be able to isolate.
"Very disappointing and expensive. I don't know if the insurance will cover it. [It was] an extra £400 [$566] in costs as well," he said.
In the Algarve, the favourite Portuguese destination of British holidaymakers, Faro airport had long queues on Sunday afternoon as more travellers decided to shorten their holiday to avoid quarantine.
"We've waited so long to come on holiday and then we've had to finish it three days early to get back because we can't quarantine for 10 days," said Patrick Morton, another British tourist who was in the same queue.
"It’s very inconvenient."
Faro airport had 55 flights scheduled to the UK on Sunday, with a capacity to transport more than 10,000 people, compared to fewer than 20 flights from Lisbon airport, according to information on the website of Portugal's airports operator ANA.
The president of Portugal's hotel association AHP, Rui Martins, said the UK's decision "will seriously compromise the entire summer".
"Hotels, particularly in the Algarve and Madeira Island, have started to see massive cancellations," he said.
The main opposition Labour Party said the traffic-light system risked imported cases of coronavirus.
“We’ve currently got countries on the amber list, which the government is basically urging people not to go to but allowing people to go to with very lax quarantine requirements when they come back," Shadow Foreign Secretary Lisa Nandy said.
“We think the amber list should be scrapped. We think it’s pointless. We think it’s confusing and that confusion is actually dangerous at the moment. It risks unravelling all of the progress that we’ve made.”
