Holidaymakers and hauliers are being warned of another day of disruption at the Port of Dover and the Channel Tunnel after two days of gridlock.
Travellers faced queues of up to seven hours to cross the Channel on Saturday as thousands of families headed to France for the summer holidays.
Traffic was “flowing normally” into the port as of 02:15 BST on Sunday, the Port of Dover tweeted.
French and UK officials have clashed over the reason for the delays.
The UK government said French authorities had failed to find enough border staff to check passports, demanding they resolve the “terrible situation”.
But French Transport Minister Clement Beaune hit back, saying France was not responsible for the additional border checks brought on by Brexit.
Families travelling to the Eurotunnel terminal on Saturday told the BBC they faced several hours of delays amid heavy congestion around Folkestone.
The Kent Resilience Forum, which coordinates the county’s emergency planning, predicts Sunday will be another challenging day, with delays and disruption for both holidaymakers and hauliers.
The Port of Dover is expected to be busy with 6,500 cars due to make the crossing, although that figure is down from 10,000 cars on Saturday.
Port officials and Eurotunnel have been working through the night to begin clearing the backlog of 1,500 lorries parked on the M20.
Natalie Chapman, from haulier group Logistics UK, said some lorry drivers had waited to cross the Channel for “well over 18 hours” in queues with no toilet facilities.
John Keefe, director of public affairs for Eurotunnel, said Saturday’s traffic disruption had been caused by an accident on the M20 on Friday.
A major incident was declared on Friday amid gridlocked routes around the Kent terminals and four-mile queues on the eastbound M2.
Kent County Council and the Road Haulage Association are urging the government to build more lorry parks to get heavy goods vehicles off the roads when there is cross-Channel disruption.
The Department for Transport said it was investing more than £30m to improve lorry-parking facilities in England.