French airports have been forced to cancel nearly one-third of their flights and delay many more as a three-day strike by air traffic controllers entered its second day.

The strike began on Sunday when a union that represents a fifth of air traffic controllers started campaigning against job cuts and inadequate investment in new technologies.

The widespread walkout soon took its toll on French airports, when on Sunday some 140 passengers had to spend the night at Orly Airport in the French capital, Paris.

The situation turned for the worse on Monday, with authorities asking airlines to cut a third of their flights at Orly and Marseille airports.

Additionally, airports at the French cities of Lyon, Nice and Beauvais were told to scrap 20 percent of their flights.

British travelers were also widely affected by the strikes, facing cancellations and up to three days of delays at the Gatwick, Heathrow and Luton airports, where most France-bound flights are operated by British Airways, Ryanair and EasyJet.

Ryanair, an Irish budget airliner, slammed the move in a statement, branding as “selfish” what it said was the 41st strike by French air traffic controllers since 2009.

The airline urged the Paris government to take action and end the "unwarranted" and "grossly unfair" action.

Air France also warned that although no rescheduling or cancellations were in sight for flights from the Charles de Gaulle airport in Paris, last-minute delays remained a possibility.

EasyJet, too, issued a statement, announcing the cancellation of 90 flights, while more disruptions were within the realm of possibility.

The strikes come weeks after a similar move in late January, when hundreds of French air traffic controllers went on a walkout in protest against labor conditions, joining forces with scores of taxi drivers who disrupted traffic by burning tires and lighting bonfires on the main streets of Paris.

The protests are the latest in a string of challenges faced by the administration of President Francois Hollande amid low economic growth and record-high unemployment.