Ryanair was among airlines that announced widespread disruptions, saying in a statement it canceled more than 400 flights affecting 70,000 passengers. The company said the strike affects all its flights over French airspace, as well as traffic in and out of French airports, and urged the European Union to reform air traffic rules.

A walkout by air traffic controllers on 3 and 4 July could mean chaos at many French airports and further afield. View on euronews

The French civil aviation agency said on Tuesday it had asked airlines to reduce flights at Paris' airports by 25% on July 3 following notification of a strike by air traffic controllers.