The French border police has blamed an “unexpected technical” incident for the hour-long bottlenecks at the port of Dover.
Authorities said they will work closely with the UK counterparts to handle surging traffic levels.
The remarks come after the Port of Dover said the queues were caused by “inadequate French border capacity.”
“Resource at the French border has increased this morning and traffic is slowly beginning to move, but it will take some time to clear the backlog,” read a statement issued by the port.
Passengers were also told to bring food supplies and avoid back roads as that “makes the situation worse, particularly for local residents.”
Chaotic scenes were seen earlier today, with queues on roads to the hub tailing back for miles.
Dover authorities blamed the situation on their French counterparts, accusing them of causing a “critical incident” and leaving holidaymakers in bottlenecks of five to six hours.
Chief executive Doug Bannister apologised for the “immensely frustrating” situation, telling BBC News he can’t vouch that the backlog will ease in the coming days.
“I really wish I could – we’re putting all the attention we possibly can do on ensuring there will be enough resources in place to manage this very busy first weekend of the summer,” he said.
People took it to Twitter to complain about the situation, highlighting the role of Brexit in the chaos.
Political activist Femi Oluwole urged those who voted in favour of Brexit to “take some goddamn responsibility.”
“If your Brexit increases the amount of checks the French need to do at Dover, you can’t blame the ‘bloody French’ for not hiring enough staff to cope with your decision,” he tweeted.
“You did this to us.”
While another urged to stop blaming the French.
Ferry operator P&O urged customers to “allow at least five hours to clear the approach roads and security checks,” while Irish Ferries told passengers they could board “the next available sailing” if delayed.
Many people have been queuing for more than six hours.
Turkish lorry driver Muhammet Turker had been at Dover since 6pm on Thursday.
“I’ve been in something like this before, but this is the worst,” he told the PA news agency this morning.
While a German man travelling back to Europe with his family told journalists they had been waiting for more than four hours in their campervan to get a ferry.
“We have a motorhome so we could go to the toilet, we could drink something, so it wasn’t that bad for us,” Steffan Harberecht told PA.
Motorists didn’t have it easier, as the AA has issued a traffic warning particularly for Dover, Folkestone while the Eurotunnel reported waiting times of three to four hours.
“Making sure you have enough fuel in the tank as well as plenty of water and snacks will be key in trying to manage the jams,” said AA’s head of roads policy Jack Cousens.
“Drivers should also keep track of congestion via the AA app and stay in touch with their travel firm to stay up to date on any advice being issued.”