Thousands of flights are set to be cancelled or delayed this week due to strike action by French Air Traffic Control.
A strike scheduled for tomorrow and Wednesday has been called off, but British Airways said controllers were still planning to walk out for 48 hours on Thursday.
The airline said that at this stage it doesn’t know how many flights will be cancelled.
"This is the second time in two months that French ATC unions will deliberately close the skies over Europe and disrupt the travel plans of millions of consumers," said Ryanair’s Kenny Jacobs.
"The timing of these strikes is designed to cause maximum disruption to consumers because there’s little or no capacity in the system to allow customers to rebook or reschedule cancelled holidays.
"The timing of these strikes during the first week of the school holidays is reprehensible."
Ryanair said in July there is little or no spare capacity to allow customers to rebook their holidays, or allow customers stranded overseas to rebook return flights.
It said these types of strikes are not permitted in the US, where Air Traffic Controllers are prohibited from striking, and are required by law to resolve their industrial relations issues through binding arbitration.
"It’s time that the French State and/or the European Union follow this example and prevent Europe’s hard pressed consumers from having their annual holidays disrupted or cancelled each year by French ATC unions," added Jacobs.
