Hundreds of Ryanair pilots may be forced to give up their holiday plans to keep planes flying as the carrier scrambles to cope with a public relations disaster after it announced it will be cancelling up to 50 flights a day until October 31, citing a “mess up” in how it schedules time-off for pilots.

The crisis caused by abrupt cancellation of more than 2,000 flights has already sparked outrage from customers and national regulators. But Ryanair now risks stirring up further anger among pilots with a threat to take back a week’s holiday in October. The airline’s dispute with pilots escalated when its chief executive, Michael O’Leary, stated he can force them to give up a week of leave.

At the airline’s annual general meeting in Dublin on September 21, O’Leary said that any that were due a four-week break in the next few months could be forced under the terms of their contract to delay one of those weeks until January, in exchange for double pay during that week.

“Pilots will still get their leave, they just may not be getting it in blocks of four weeks from October-November,” O’Leary said. “We will be looking to writing to our pilots saying – to the 500 pilots who have four weeks’ leave in October – I’m sorry we have to take one back. You can have three weeks’ leave in October and you can carry forward the fourth week of leave.”

O’Leary said the company had known about the change in flying hours – overseen by the Irish Aviation Authority, under EU rules – since late 2016 or early 2017. Although Ryanair had agreed with pilots that they could take a four-week holiday as it moved to the new system, O’Leary said an over-allocation of leave had led to a shortage of standby pilots on its roster. The havoc has left the airline with only 20 or 30 standby pilots on its roster instead of the usual 150.

O’Leary acknowledged the airline is increasing pilot pay in Dublin from October as attempts to poach Ryanair crew by Norwegian Air came to light. Dublin-based captains can expect a total increase in their annual take-home pay of €22,000. Pilot pay will also increase in Stansted, London, as well as in Berlin and Frankfurt. In the meantime, Ryanair is also facing a bill of up to €25m in compensations to passengers.

All of this comes as a group of pilots turned down an offer of up to £12,000 pay to keep flying during their scheduled leave, the Guardian reports. The letter from pilots to Ryanair had signatories from bases across Europe not only turning down the airline’s offer of a tax-free cash bonus but also warning that they are prepared to “work to rule” - refuse to do anything outside their contractual obligations, which would involve working days off, arriving for shifts early to avoid delays or even answering calls when they are not at work.

At the annual meeting, however, O’Leary appeared unwilling to show any good will in the standoff, threatening to cancel pilots’ time off instead. “We don’t need their agreement,” O’Leary said. “It is part of our working agreements with the pilots and our rostering agreements that if we need to take back holidays – with reasonable notice we can do so.”

O’Leary dismissed suggestions of industrial action from disgruntled pilots seeking improved employment terms. He said that there “isn’t a bad relationship” between Ryanair and its pilots. “We asked on Monday for volunteers to work days off… We have had huge cooperation and support from pilots.”

O’Leary also rejected claims that the airline has seen more than 700 pilots quit in the past year. According to him, some 125 pilots will start work this week and a total of 500 new pilots will join by the start of its summer season next March, the Financial Times reports.

Ryanair’s 4,200 pilots – many of whom work as agency contractors – are not unionized, therefore, could face the risk of being fired for threatening the company. But many believe the airline is not in a position to take drastic measures because it would exacerbate the problem and the resulting reputational damage could be extremely long lasting both in terms of customer and shareholder confidence.

Meanwhile, Ryanair pilots are being encouraged and offered advice by colleagues at rival airlines across Europe, amid concern that the carrier is leading a “race to the bottom” that has seen terms and conditions deteriorate across the industry.