Portugal will be removed from the green list at 4am on Tuesday (8 June), meaning travellers must arrive back before then or they will need to self-isolate at home for 10 days.
Nearly double the usual total of flights are scheduled to depart from Faro Airport in the Algarve for the UK today as tourists scramble to leave the holiday hotspot.
But some travellers wanting to beat the quarantine deadline are being hit by a combination of sold-out flights and available seats being sold at inflated prices.
Ryanair is charging £285 for a flight from Faro to Bournemouth on Monday, but just £17 on Wednesday.
EasyJet flights from Faro to Gatwick are £227 on Monday and £53 on Tuesday.
A seat on British Airways’ last flight on Monday, from Faro to Heathrow, costs £349, although the airline is allowing people booked on flights from Portugal to the UK between Tuesday and Sunday to travel on Monday for no extra charge.
Tourists have also reported difficulties obtaining the pre-departure tests required by the government for people arriving in the UK.
‘We have been under extreme stress’
Many holidaymakers and travel firms expressed anger when the announcement on Portugal was made last Thursday, as it came just 17 days after the ban on international leisure travel was lifted.
Alan and Lisa Pechey, from Cambridge, who were on holiday in Lisbon, paid a total of £800 to fly back to Gatwick on Monday, earlier than planned.
Mrs Pechey, 66, told the PA news agency: “It was really expensive and I think the Government was totally unfair to throw that at us on Thursday because it really spoiled our holiday, totally.
“We had flown out on Monday for a relaxing break, but from Thursday onwards we were under extreme stress.”
Ana Pacheco, 28, from Islington, north London, who was on holiday near Porto, paid £300 for her flight home.
She said: “I lost money on this trip, about £300 extra, because I was due to come back tomorrow evening, so it is quite annoying.
“I think there should have been extra time added on for us to get home – at least a week would have been better.”
Travellers ‘rushing’ to get home
Marcus Gardner, 26, from Battersea, south London, who flew to Gatwick from Porto, said: “Our flight was much busier than before – going there only a few people were on the plane but coming back it was full capacity.
“A lot of people were rushing to get home and at the airport there were loads of people waiting for a flight.”
The Department for Transport said the situation in Portugal “required swift action to protect the gains made with the vaccine rollout”.
It stated that the positivity rate for coronavirus tests in Portugal had nearly doubled since the travel lists were first created four weeks earlier.
The DfT added that 68 cases of the Indian mutation, which is also known as the Delta variant, have been identified in Portugal.
Separate Test and Trace figures show 200 arrivals from Portugal were tested between May 6 and May 19.
Three of those people tested positive for coronavirus.