More than 200 easyJet flights have been cancelled to Portugal due to a three-day strike by cabin crew at the height of the summer peak.
A total of 232 out of 1,138 flights to and from the country have been grounded by the budget carrier.
The airline has cancelled a total of 27 return flights between the UK and Portugal in advance for the strike period, according to easyJet.
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Flights to Portugal operate from several UK airports, including Bristol, Gatwick, Glasgow, Luton and Manchester. No flights from Belfast International are affected.
Cabin staff in Portugal warned last month a strike from August 15 to August 17.
Reasons for the action include a lack of roster stability, insufficient staffing and pressure to work overtime for commercial purposes, according to the civil aviation flight personnel union SNPVAC.
EasyJet Portugal told Reuters on Wednesday it had scheduled 1,138 flights across the three days but about a fifth of them had to be cancelled due to the strike.
“We regret that, due to the unnecessary strike action planned by the SNPVAC union and in order to minimise the impact of the disruption on the day of travel for our customers, we have had to cancel some of the flights planned to operate during the period of the collective action,” the airline said.
EasyJet added in a statement: “We are extremely disappointed with this needless strike action, especially at this important time of the year for our customers.
“Our priority has been to try and minimise the impact of this strike action on our customers, which included cancelling some flights in advance in order to allow them to rearrange their travel plans.
“Customers whose flight has been affected have already been contacted a number of days ago with their options to rebook or receive a refund.
“We also advise customers travelling to and from Portugal on 15, 16 and 17 August to check the status of their flights on the easyJet Flight Tracker.”
EasyJet has 19 aircraft based in Portugal, as well as more than 800 staff based there.
The industrial action came as official data showed a record first half of there year for inbound tourism to Portugal.
International arrivals rose by 7.5% year-on-year between January and June with more than 8.8 million staying in hotels in the period.
June alone saw almost two million foreign visitors, up 6.9% from the same month last year.
UK travellers represented the largest share of total arrivals, ahead of the US and Spain.
Portugal’s National Statistics Institute (INE) was reported by Reuters as saying that the hotel sector registered more than 14 million guests, including domestic travellers, while total hotel revenues increased 12.3% year-on-year to €2.8 billion.
INE also said the number of passengers who travelled through Portuguese airports in June rose 5.6% to 6.7 million compared with the previous year.