Some passengers who arrived on Saturday were still stuck on Sunday morning.

The port said it estimated waits of between six and eight hours for coach passengers, depending on the ferry operator.

Officials cite slower border processing and a higher-than-expected number of coaches as causes of the delays.

The port said it expected a smaller number of coaches on Sunday. It said more than 300 coaches departed on Saturday and that all tourist cars and freight were processed successfully.

The disruption at Dover began on Friday night and continued throughout Saturday.

On Sunday morning, the port said roads to the port had been cleared and cars were taking around one hour to get through – but coach passengers remain particularly badly affected. P&O Ferries said coaches were being sent to a “buffer zone” to wait before heading to the port.

Some coach passengers have provided BBC News with descriptions of travel “carnage”, and said they had waited for as long as 14 hours to board a ferry to France.

Holidaymaker Jennifer Fee said on Saturday evening that her coach was “turning around and going back to London” having been told there was “no chance of a ferry today”.

Ms Fee sent BBC News footage of passengers camped out on the floor of a service station in nearby Folkestone – where coaches had been “stacked up” due to delays at the port.

Home Secretary Suella Braverman told the BBC’s Sunday with Laura Kuenssberg show that the government was in close contact with port authorities and that she expected the problems to ease soon.

She said she sympathised with families and school children trying to get away on Easter holidays. “It is a busy time of year… this will require a bit of patience,” she said, adding that the delays were a result of a “combination of factors”.

Labour’s shadow levelling-up secretary Lisa Nandy told Sky News that issues such as port delays could have been avoided “if the government got a grip, got down to brass tacks and started doing the actual job”.

Many coaches stuck in Dover have been carrying schoolchildren from different parts of the UK on school trips abroad.

One driver taking a group from Cardiff to Austria said they had been in the vehicle for 14 hours.

Anthony Jones described a “frustrating” situation with “no communication”, telling the BBC that it appeared cars and lorries were passing through border checks ahead of coaches.

The management for the port apologised for the “prolonged delays” and said the tailbacks were being cleared.

On Saturday evening the port’s chief executive, Doug Bannister, said: “My ops team is anticipating that we will get through all the backlog, including all the people that wanted to travel today, overnight.

“The ferry operators are laying on additional sailings overnight to try and accomplish that, so hopefully by about midday tomorrow we’ll be back to normal operations.”

Ferries usually have a longer gap between sailings at night – but they were “basically just running back and forth to clear as much as they can”, the port’s communications team added.

Officials explained that long border processing times were partly to blame for delays – combined with the bad weather cited by ferry companies on Saturday.

Ferry companies had received 15% more coach bookings for the Easter period than had been expected, the port said. Boarding coachloads of separate passengers is much slower than boarding cars.

Responding to the claims of lengthy delays in border checks on Saturday, officials in northern France said there were “no difficulties that we know of”, but that lots of coaches had arrived to travel at around the same time.

All border checkpoints were operational and border police had changed some car checkpoints into slots for coaches, they added.

Simon Calder, travel correspondent at the Independent, said processing times since leaving the EU had increased sharply “and that would seem to explain the delays”.

An EU border at Dover meant things were “gumming up”, as each individual passport had to be inspected and stamped after Brexit, he told the BBC.

Delays have been compounded by coachloads of passengers needing to disembark to have their passports checked.

Asked whether the port delays were a result of Brexit, Labour’s Ms Nandy said: “The point is not whether we left the European Union or not… the point was that we left with a government that made big promises and once again didn’t deliver.”

Despite the disruption, some passengers stuck at a service station in Folkestone appeared to be in decent spirits, and were seen dancing to pass the time.