Flights and train services in France are likely to be disrupted by a nationwide general strike called by unions across the country.
One of the main French air traffic controller unions is expected to take part in the industrial action, which will take place throughout Tuesday (September 12).
British Airways said in an advisory to passengers: "Unfortunately, if the threatened strike does go ahead, we are likely to cancel some flights as a result of the strike action and other short-haul flights may also experience some disruption, given how many flights from numerous European airlines would normally use French airspace each day.
"We will be using larger aircraft, where possible, to help affected customers and are doing all we can to reduce the levels of disruption."
Easyjet said: "Like all airlines, our flights to and from French airports, as well as those flying in French airspace, could be affected.
"We are doing everything possible to minimise the impact of the strike on our customers, and we advise all passengers to allow plenty of extra time to get to the airport and consider alternative transport options where possible, as public transport services may be affected by the strike."
Air France, which is also being affected by an ongoing strike by its pilots, added: “We expect limited disruptions on our domestic flight programme. Last-minute delays and cancellations can be expected too.”
SNCF rail services in France may also be affected by the strike.
French unions are unhappy at new president Emmanuel Macron’s plans for labour reforms, which have been called a “declaration of war” by the CGT union.
Carlson Wagonlit Travel said in an advisory to clients: “Unless averted, flight delays and disruptions are to be expected. Travellers are encouraged to check their travel itinerary and the status of their flight before departure.”