On Tuesday it was announced that up to 12,000 British Airways workers will lose their jobs, which is more than one in four employees. The reductions represent about 15 per cent of Ryanair's workforce and would include pilots and cabin crew.
Mr O'Leary said customers may have to wait up to six months for cash refunds for cancelled flights.
Ryanair said that it would challenge this state aid "doping", which it said was in breach of European Union rules and which would "distort Europe's level playing field in airline competition for many years".
The European Parliament's transport committee quizzed the head of the EU Aviation Safety Agency (EASA) on Monday (18 March) about the ongoing investigation into a crash that prompted agencies around the world to ground Boeing MAX aircraft.
As a direct result of the unprecedented Covid-19 crisis, the grounding of all flights from mid-March until at least July, and the distorted State Aid landscape in Europe, Ryanair now expects the recovery of passenger demand and pricing (to 2019 levels) will take at least 2 years, until summer 2022 at the earliest.
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The airline has also hit out at what it calls "unlawful and discriminatory State Aid" offered to a number of legacy airlines by their governments. United Kingdom discounter EasyJet dropped as much as 7.3 per cent, while IAG, the parent of British Airways, declined as much as 4.6 per cent. Carriers across the region are asking for help to survive the coronavirus crisis that has grounded much of Europe's air traffic, endangering not only the airlines but connections that keep tourists flowing to Rome and Paris and help power Germany's export economy.
Ryanair said that when scheduled flights do return to Europe "Consumer confidence will be impacted by public health restrictions, such as temperature checks at airports and face coverings for passengers and staff on board aircraft", but added that traffic will be stimulated by "significant price discounting".
"Ryanair seems to have done a u-turn on its ability to weather the Covid storm", it claimed. The company is working on reducing deliveries of 737 Max narrow-bodies from Boeing and Airbus SE A320-series jets from leasing firms.
"If we are going to carry a third less passengers this year, I am afraid we are going to need fewer pilots and fewer cabin crew", he said.