 The blockade is due to end at 0700 GMT on Friday |
Thousands of tourists remained stranded in Calais on Thursday night as striking French sailors continued blockades, ferry operator P&O says. No ferries docked on Thursday because of French protests at plans to allow foreigners into the merchant navy.
The blockades have also caused road chaos with thousands of trucks stacked up in Dover and Calais.
The action follows similar blockades on Wednesday, which were part of a separate dispute over fishing quotas.
Lorries stacked up on the M20 in Kent and there were more than 10 miles (16 kilometres) of jams outside Calais.
Tourists were being turned away from the ports by police on both sides of the channel.
Among those stranded were hundreds of schoolchildren trying to return from trips to France.
A spokesman for P&O said the company had done everything it could to force the French authorities to resolve the situation, including gaining a court injunction against the sailors.
 | Time and time again, British trade is being affected by wildcat militancy, and we are frustrated because the French authorities seem to do nothing about the problem  |
One of its ships - the Pride of Aquitane - left Dover at 1300 GMT to "test the water" but the sailors refused to allow it to dock.
The blockade is due to last until 0700 GMT on Friday but P&O officials are hopeful the strikers will have "lost interest" by them.
Spokesman Chris Laming said the company had been in contact with the French authorities, and understood there was a chance that riot police might be sent to Calais to break the strike.
"This blockade is unacceptable," he said.
"Time and time again, British trade is being affected by wildcat militancy, and we are frustrated because the French authorities seem to do nothing about the problem."
All services to and from Dover to Calais have been hit by the strike and sailings to Cherbourg are also affected with Brittany Ferries forced to cancel a service from Poole.
Ferry cancellations
French unions say the plan to liberalise merchant shipping threatens jobs and safety.
The ferry line SeaFrance, a wholly-owned subsidiary of French railways group SNCF, said its five ships were restricted to Calais as a result of the strike.
And the action was being followed by 80% of its 1,500 employees.
Wednesday's blockade by fishermen led to more than 40 ferry cancellations, and was likely to have cost UK industry more than �1m, the Freight Transport Association said.