STRIKING French fisherman have caused disruption to cross-Channel ferries and forced the implementation of Operation Stack.
The militant mariners are blockading ports at Boulogne and Calais, meaning ferry sailings from the Port of Dover have been severely affected.
A Dover Harbour Board spokesman said: "Due to industrial action at the Port of Calais services with P&O Ferries and SeaFrance are subject to disruption.
"The Port of Boulogne is also affected by this industrial action, therefore LD Lines diverted their 1pm sailing to Dieppe and subsequently cancelled tonight's 6pm sailing. All booked passengers are advised to contact their ferry operator for further details."
At this stage it is not known if Norfolkline crossings to Dunkerque will be affected by the dispute. DHB terminal control explained the company's vessel Maersk Delft if currently sailing to the French port to see if it is still accessible.
Delays, diversions and cancellations mean Kent Police has little choice but to introduce Stack to deal with the backlog of freight traffic which is likely to build up on this side of the Channel.
Phase two is currently being put into operation, closing the M20 coastbound between Junctions 8 for Leeds Castle and 9 for Ashford. Non-freight traffic is diverted onto the A20.
A spokesman for Kent Police said: "A freight ticketing system will operate in the Stack queue, with strict enforcement conditions, operated by both police and the Port of Dover.
"Any lorry driver arriving at Dover without the correct ticket will be turned away from the port and told to drive back to the rear of the M20 freight queue."