Internal flights could be abolished in France if the same journey can be made by train in less than 2 hours and 30 minutes.
French lawmakers have approved a bill that will ban short domestic flights in an effort to lower the country's carbon emissions.
Under the proposals, air routes will be abolished if the same journey can be made by train in under two-and-a-half hours.
The climate bill is aimed to remove domestic flights between the capital, Paris, and other cities, such as Nantes, Lyon, or Bordeaux. However, the law does provide exceptions for connecting flights.
Supporters of the bill had proposed that the law be extended to cover domestic flights where the same train journey lasts up to 4 hours.
"We have chosen [the time limit] because four hours would isolate territories that are often landlocked like the Massif Central," argued France's Minister for Transport Jean-Baptiste Djebbari.
But some lawmakers have criticised the bill for its likely impact on the air travel industry, already under intense strain during the global COVID-19 pandemic.
In May 2020, the French government forced Air France to give up domestic routes affected by the bill in return for financial support.
Andrew Charlton, managing director of Aviation Advocacy Geneva, told Euronews that the law had been poorly explained to the industry.
"There's an enormous balance [between environmental concerns and business concerns] that has to be struck ... it's an extremely complicated matter," Charlton said.
France's National Assembly on Saturday after debate and will go to the Senate before a final vote in the lower house of the French Parliament.