The Irish carrier has been under fire in the press since last week when it announced that it was cancelling 2,100 of 103,000 flights over a six-week period running into October.

By Wednesday last week it said it had rebooked more than 55% of the estimated 315,000 passengers, impacted on to other flights.

The issue, which saw nearly €1.4 billion wiped off Ryanair’s market value, has been blamed by boss Michael O’Leary on too many staff taking holidays during this period, following a change in the rules.

However, reports have emerged alleging that many pilots left the airline to join its rivals as they were unhappy with pay and conditions. One report by City AM stated that as many as 140 had left Ryanair for Norwegian since the start of the year.

But while Ryanair might be suffering at the moment, OAG senior analyst John Grant warned that other smaller airlines, which do not have the same market share, could soon feel the pain as well. He said: “There is a fundamental shortage of pilot capacity that’s been growing for some time. In the next 20 years there’s going to be a need for 620,000 pilots globally.”

Grant added that OAG data revealed this summer had seen an extra 1.1 million scheduled flights globally, with 251,000 more in Europe.

Meanwhile, nearly half of all pilots are set to retire in the next 10 years and Asian airlines are offering increasingly attractive deals to poach pilots to meet their own demand.

Grant said: “It is a serious issue in terms of costs for all airlines. When you get a scarcity of resource then the price goes up, therefore the operating cost of a carrier goes up.”

He said he thought costs would be passed on to the consumer, resulting in higher flight and holiday prices.