Ryanair and airline boss Michael O'Leary have been accused of insulting the Government's Transport Committee by failing to attend a meeting over the cancellation controversy.
Mr O'Leary was invited to attend the Oireachtas committee meeting on Wednesday along with representatives from the Irish Aviation Authority and Irish Airline Pilots' Association to discuss the impact of the cancelled flights on passengers.
However, committee chairman Fergus O'Dowd TD, told members that Mr O'Leary had declined the invitation.
"He said he totally regretted the disruption caused.
"It is disappointing he is unable to attend this meeting. I hope he will be able to accept the invitation at some point in the near future," said Mr O'Dowd.
Mick Barry TD responded: "It should be noted the committee invited Ryanair and Michael O'Leary. It is an insult they haven't come."
The airline has cancelled tens of thousands of flights through to March this year because of errors in how pilots are rostered for work.
This has disrupted the travel plans of 700,000 passengers.
Ryanair announced its first wave of 2,100 cancellations in the middle of September, after it rearranged pilots' rosters to comply with new aviation rules requiring a change in how their flying hours are logged.
Towards the end of September it announced 18,000 further flights would be cancelled over the winter season.
Ryanair has also clashed with its pilots over their working conditions.
Despite the disruption caused by cancelled flights and the ensuing PR disaster, Ryanair recently announced it flew 11.8 million people in September, 10% more than in the same month in 2016.