At 18:00 UTC on Wednesday 21 March, some French air-traffic controllers will stop work in protest against labour reforms.
The action will continue until 05:00 UTC on Friday 23 March.
All airlines have been told to reduce their operations by 30% in flights to/from Paris CDG, Paris ORY, Beauvais, Bordeaux, Toulouse, Marseille, Lyon & Nantes.
The greatest impact is expected to be in the south and west of France, affecting flights linking the UK with Spain, Italy and Switzerland.