RYANAIR chief executive Michael O'Leary warned that flights will be grounded next year, if the British Government fails to avoid a hard Brexit.
The Irish airline reported a healthy 9 per cent increase in passenger numbers to 130.3 million - considered a major performance indicator for the airline industry - in their annual results for 2018.
But 2019 could be a lot tougher, O'Leary warned, as the possibility of a chaotic exit from the European Union continues to be "downplayed in the UK".
"We hope to see a smooth transition, but I think that there is a real challenge for the government [in Britain]," O'Leary said. "There is a real risk of a hard Brexit in March 2019 and the risk is being downplayed in the UK.
"If that happens there is a real chance of disruption to flights in April 2019: I hope it doesn't happen but flights could be grounded."
The airline is continuing to assume their will be a hard Brexit and is planning for one, O'Leary warned.
Ryanair full-year profits after tax rose 10 per cent to €1.45bn despite being forced last year to cancel flights and ground planes due to errors in the staff rota left them short of pilots. The disruption cost Ryanair €261m.
The Irish airline also was subject to a one-day pilot strike in Germany in December and three days of cabin crew strikes in Portugal in March and April this year.
While O'Leary insisted that the threat of further pilots strikes had been abated during recent negotiations, he stressed that profits next year are also likely to be hit by a €400m hike in the airline's fuel costs.
O'Leary also revealed that Ryanair's the recently signed co-operation agreement with Aer Lingus means passengers from London and other European cities will be able to access cheaper fares to the US before the end of this year.
"The great advantage is you can pre-clear immigration for the US in Dublin and avoid long queues," O'Leary added.
