Channel Tunnel shuttle train services run by Eurotunnel are facing the threat of strike action by French unions over the bank holiday weekend.
Eurotunnel said it was not taking further bookings for Calais to Folkestone journeys for Saturday, Sunday and bank holiday Monday.
But the company said it still hoped to run a full service over the weekend.
Eurotunnel said the French workers were demanding an 8% pay rise and were threatening to strike from Saturday.
A company spokesman said: "We have suspended Folkestone to Calais bookings in order to protect the bookings we already have and we fully expect to carry on as normal."
Eurotunnel added that it was taking all steps to mitigate any disruption. It was ensuring that British train drivers were available and was also looking at the possibility of sending British staff to man the terminal in France if necessary.