The majority of Ryanair pilots are reportedly set to turn down an offer of up to £10,000 to work on their scheduled days off over the course of the year.

On Tuesday (19 September), the Irish carrier offered a substantial bonus to pilots who choose to make themselves available to plug gaps in the schedule, after a shortage of pilots has forced the Irish carrier to cancel between 40 to 50 flights a day over the next six weeks.

More on Ryanair

In an internal memo circulated by the airline's chief operations officer Michael Hickey, pilots who have already been assigned a month off are requested to work either one or two blocks of five days to avoid further cancellations.

Pilots, both employees and contractors, who choose to work additional days will be rewarded with a bonus as long as they remain working with the Irish airline until October next year. Captains will be entitled to a gross bonus of €12,000 (£10,653), with first officers set to receive half that amount.

However, according to the Belfast Telegraph, the majority of pilots based at Dublin airports are unlikely to accept the offer, while Ryanair pilots based in Italy are already understood to have turned down the proposal.

Should the majority of the airline's 350 pilots based at Dublin airport follow suit, their decision could put them at loggerheads with the carrier's management, straining an already delicate relationship.

More than 120 pilots attended three meetings in Dublin earlier this week, where an industrial action ballot over crowded flight schedules and other working conditions at Europe's largest carrier were discussed.

On Monday (18 September), budget airline Norwegian Air, one of the carrier's direct rivals in the budget airline sector, claimed over 140 pilots had joined its ranks this year after leaving Europe's largest airline. Norwegian is building a new hub at Dublin airport, Ryanair's home base, and is threatening to poach more of its pilots in coming months.

However, in a press conference on Monday afternoon, Ryanair chief executive Michael O'Leary quashed reports that the airline had lost a slew of pilots to Norwegian.

"We are not short of pilots, we have 4,200 of them. What we have messed up is the allocation of holidays. We don't have enough pilots in September and October to allocate the leave."

The memo also asked pilots who have booked next month off to confirm their availability by Wednesday (20 September). It is understood some pilots have already had their leave cancelled, which is within the airline's rights in exceptional circumstances.

Meanwhile, the airline has also reportedly contacted pilots who previously applied for jobs with Ryanair but did not accept an offer of employment. The carrier in understood to be asking pilots whether they declined the offer because their preferred base was not available and whether they would be willing to reconsider, should that location be available now.

Flight cancellations blamed on poor planning

Ryanair has blamed the raft of cancellations, which will affect approximately 400,000 passengers across 2,000 flights, on its decision to shift its holiday year to run from January to December, rather than the current system, which sees it run from April to March.

As a result, the airline said it had to allocate annual leave to pilots in September and October.

However, that version of events was contested by the Irish Air Line Pilots' Association (Ialpa), which described as "strange and unsustainable" the airline's explanation that the disruption was due to difficulties dealing with pilots' entitlements to annual leave.

The industry body said the changes were flagged up to the airline a year ago, when the Irish Aviation Authority (IAA) and all Irish airlines were forced to align with European flight time regulations.

"It seems clear that Ryanair has failed to plan properly for the implementation of the regulations," Ialpa said.

IBTimes UK has contacted Ryanair for a comment.