There has been more serious disruption for people seeking to cross the English Channel via Calais after striking ferry workers again forced the French port to close.
It led to long jams on approach roads in northern France, including the A16 motorway as lorry drivers had little choice but to wait.
In England too thousands of vehicles have also been stuck on the M20 motorway approaching Dover.
However the Channel Tunnel has remained open on Wednesday, unlike the previous day when it was blocked for three hours.
Drivers have been advised to defer their journeys and seek alternative routes.
The workers from MyFerryLink are trying to prevent job cuts after the firm was sold to a Danish group – and a serious escalation of the dispute is now threatened.
“We will block motorways approaching the tunnel for 48 hours by various actions,” said Eric Vercoutre, a union leader from the Syndicat Maritime Nord (SMN).
“We will block the motorways and continue to block the regional economy… things need to move more for the (French) president to take the issue in hand,” he added, stressing that aim was to “keep the ships” and safeguard “600 jobs”.
There are fears for the safety of drivers coping with stifling temperatures as they sit in long traffic jams – not to mention migrants who have again been trying to climb aboard vehicles, desperate to get to England.
Britain’s Road Haulage Association has called for French troops to be deployed if that was needed to break the strike, according to a report in The Guardian.
Earlier the truckers’ organisation had demanded an EU response to seek a solution.