The Paris Airport authority, which manages Charles de Gaulle and Orly airports, and the Eurostar rail service both warned on Wednesday of major disruption to travellers, adding to pressure on holidaymakers already facing delays across Europe.
The Paris Airport body sent a message on its Twitter account saying that software problems were impacting border controls checks, and this in turn would lead to delays.
Eurostar, which runs train services linking London to Paris, also issued a similar warning.
"Our stations are very busy today. Passport and security checks are taking longer than usual due to issues with French authority control systems," it said on its Twitter account.
Airports across Europe have struggled to cope with a post-pandemic rebound in demand, but British airports are facing a particularly difficult week as a school half-term holiday combines with a long public holiday weekend to mark Queen Elizabeth's 70 years on the throne. (Reporting by Gus Trompiz and Richard Lough; Editing by Sudip Kar-Gupta)