Ryanair has warned customers that it will cancel as many as 50 flights every day over the next six weeks.
The decision has been taken due to a huge backlog of annual leave which has seen large numbers of the airline’s staff book holidays towards the end of the year.
Punctuality fell below 80% over the last fortnight, with the budget airline also blaming air traffic control delays and strikes, and bad weather.
A spokesman admitted the figure is ‘unacceptable’, but added that cutting 2% of its timetable would help performance while allowing staff to go on holiday.
Passengers affected will be offered alternative flights or refunds, Ryanair said.
The company explained that its holiday year had been changed from April to March to a calendar year starting on January 1 2018.
This led to many workers booking time off before the end of the year so they could use their daily allocation.
Customers have taken to social media to complaining about their treatment, with some saying they were unable to cancel a hotel booking and left out of pocket.
Maria Joanna Suquitana said guests heading to her brother’s wedding in Italy had their flights cancelled hours before departure.
She wrote on Facebook: ‘We were forced to rent a van from Germany and drive 16 hours because we just can’t trust to fly with you again. Most stressful days of our lives.’
Karen Naughton Brill said her daughter’s plan to celebrate her 21st birthday in Amsterdam was ‘ruined’ when the flight was cancelled.
She said: ‘She’s gone to bed in tears, rang hotel, can’t get refund too short notice, same with parking, Anne Frank house tickets etc etc all non-refundable.’
Robin Kiely, head of communications at Ryanair, said: ‘We have operated a record schedule and traffic numbers during the peak summer months of July and August but must now allocate annual leave to pilots and cabin crew in September and October while still running the bulk of our summer schedule.
‘This increased leave, at a time of ATC capacity delays and strikes, has severely reduced our on-time performance over the past two weeks to under 80%. By cancelling less than 2% of our flying programme over the next six weeks, until our winter schedule starts in early November, we can improve the operational resilience of our schedules and restore punctuality to our annualised target of 90%.
‘We apologise sincerely to the small number of customers affected by these cancellations and will be doing our utmost to arrange alternative flights and/or full refunds for them.’