Ryanair said it was forced to cancel 55 flights overflying France today because of another day of strikes by air traffic controllers there.
In a video message, Group CEO Michael O'Leary said that in the first wave of departures this morning, 200 of more than 500 flights around Europe were delayed as a result of the action.
He said today is the 64th day of industrial action by French air traffic controllers so far this year.
"The impact of this on our operations today is terrible," the Ryanair boss said.
"These disruptions are avoidable."
The CEO once again called on European Commission President, Ursula Von Der Leyen, and other commissioners to take action to stop overflights being disrupted by French ATC strikes.
He said the airline had gathered and submitted two petitions with 1 million and 1.5 million passenger signatures respectively and so far there had been "no action" by the Commission.
"It is time the EU took action," he added.
Mr O’Leary also apologised to passengers for the disruption.
