Flights between the UK and northern France face disruption today due to a strike by French air traffic controllers.
Airlines are also warning that flights over France to other countries might also be affected by the walk-out at the CRNA Nord tower, which manages airspace in the north of the country.
At the time of going to press, flights to some French airports were being delayed by between 30 minutes and an hour.
The worst hit airport appears to be Paris Orly, where flights are delayed by an average of 55 minutes. Around a third of flights have been cancelled.
Other airports affected are Paris Charles de Gaulle, Brest in Brittany, Lyon and Lille.
The strike is due to last until Tuesday at 6am.
EasyJet said: “We expect that there will be delays and some disruption due to the industrial action, therefore we advise all customers to check the status of their flight on our flight tracker either on our mobile app or website: www.easyjet.com/en/flight-tracker.”
Jet2 said: “We will be working hard to ensure that the impact on our flights is minimal, however, you may encounter some disruption if you are travelling during this time.
“Please be prepared for possible longer than normal waits onboard your aircraft to depart.”