Queues began building at the Port of Dover on Monday morning after chaotic scenes of bumper-to-bumper traffic for miles on Friday.
Government ministers have accused French authorities of not having enough officials at the border to check passports, leading to delays.
Ferry operator DFDS told passengers that there were “queues of around an hour" for French border checks on Monday morning, and to “allow a minimum of 120 minutes before your departure to complete all controls".
Dover traffic jam and chaos for Summer getaway 2022
P&O Ferries wrote on Twitter: “The queues have picked up and it is taking approximately one hour to clear passport control."
Friday’s scenes were exacerbated by a serious collision on the M20, officials have said.
Toby Howe, senior highways manager at Kent County Council and tactical lead at Kent Resilience Forum, said the current queues at the Port of Dover were "normal for a Monday morning".
He told BBC Radio 4’s Today programme that next weekend is likely to be "very busy".
Mr Howe said: "It’s the second busiest getaway weekend of the summer holidays.
"As we’ve just found out the weekend just gone, traffic numbers travelling across the Channel were back to pre-pandemic levels and with the increased checks it is slower to get through, so it takes very little to cause those tailbacks."
On what the rest of the summer could bring, he said: “Basically it’s a very vulnerable situation, it takes very little to cause further issues."
Speaking on Sky News, the Education Secretary, James Cleverly, said the government believed the problems were caused by French staffing shortages.
“The fact they are taking so much longer now is causing these problems that can and should be resolved,” he said.
“We’re working to get this resolved but ultimately, this is something that we do need the French authorities to increase the number of people doing these checks.”
Severe delays were also reported at Folkestone, with the head of roads policy for the AA calling it “the hotspot of holiday hell”.
Jack Cousens said that drivers were waiting for several hours in traffic before reaching the Eurotunnel on Sunday.
Among those caught up in the traffic was Andrew Dyer-Smith and his family, who spent 21 hours in traffic while heading to France for a summer holiday.
“We arrived at Folkestone at 9am [on Saturday] morning for a train at 10.30 and then have been slowly crawling along for the last 21-plus hours,” he told the BBC.