Ferries between Dover and Calais have been suspended due to a strike by staff at the French port.
The 24-hour closure of the Port of Calais began at 8am on Thursday.
Ferry operators DFDS and P&O Ferries normally run a total of up to 50 sailings per day between Dover and Calais.
DFDS has switched one of its Calais ships to the Dover-Dunkirk route to provide extra capacity.
Freight vehicles and passengers due to travel between Dover and Calais with DFDS on Thursday are being shipped on the next available Dover-Dunkirk sailing instead.
The Port of Dover said in a statement: “We will continue to monitor the situation closely in liaison with our ferry partners and the Port of Calais.
“Please note that there may be delays to services when the Port of Calais reopens and services resume to normal.”