A school was forced to cancel its ski trip after being stuck in severe delays at Dover, a parent said today.
Students were held up in a coach for 12 hours, only to be called to the port and told there was a further 12 hour wait.
Louise, whose daughter was on the trip, described the delays as "horrendous" after the coach had to turn back around - leaving pupils bitterly disappointed.
She tweeted: "They have had to give up, cancel their skiing trip and come home. A year of buildup for nothing."
It comes after a teacher waiting with a coach full of 42 children labelled the conditions as "disgusting", saying they had no water, food or toilets since arriving at the port.
And Gillian Charlton told how her 13-year-old son, Ned, and his friends have been in a holding area since arriving at around 7.30pm last night.
She said the children are only allowed to get off to use a portaloo and were given one KitKat at midnight.
Extra sailings were run overnight to try and clear the backlog, which has left passengers stuck in traffic for hours.
But this morning, the port estimated some travellers could still face waits of up to eight hours, depending on the ferry operator.
A port spokesman said: "The additional sailings have assisted in clearing some of the traffic, although currently both DFDS and P&O have two full lanes of coaches in the port before French border controls, with a processing time of about 4.5 hours.
"P&O have some coaches waiting at the cruise terminal and DFDS have some at service stations in Kent.
"Once coaches are processed in an operator's lane, more are being sent to the port. Currently, the estimated total time is six to eight hours dwell time."
Taking to Twitter, one parent tagged ferry operator DFDS and demanded to know whether they would be providing her child with food or water.
Abbie said: "My child has been on a coach for 18 hours!! And only just in dock!! What is the wait time now until boarding? What are you doing to get coaches through?
"These kids have had no food. Will you be giving them food and water?"
Meanwhile, teacher Sarah tweeted: "An honest assessment of the situation would be nice. 42 kids, 12 hours since arriving at Dover, some of it at stop 24 still not at passport control.
"No water, no food, no toilets since getting to port and a child with a kidney condition it's disgusting."
And one parent asked P&O Ferries: "My son and a coach load of his friends plus their poor teachers have been parked up at an industrial estate since last night. No sign of moving. They were due to sail last night.
"What are you doing to help? This is absolutely abominable treatment."
P&O Ferries apologised to customers on Sunday, saying some will face waits of four to five hours.
The port previously declared a critical incident and said the delays were "due to lengthy French border processes and sheer volume".
Ms Braverman told Sophy Ridge On Sunday on Sky News that it would not be fair to view the delays as "an adverse effect of Brexit".
She said: "What I would say is at acute times when there is a lot of pressure crossing the Channel, whether that's on the tunnel or ferries, then I think that there's always going to be a back-up and I just urge everybody to be a bit patient while the ferry companies work their way through the backlog."
She also downplayed any fears that delays at Dover could become a regular occurrence that risks ruining school holiday plans.
She suggested that in general "things have been operating very smoothly at the border".
Speaking on the BBC's Sunday With Laura Kuenssberg programme, she added: "I don't think this is the state of affairs to go forward.
"I think we have got a particular combination of factors that have occurred at this point in time.
"This will ease. I ask everybody to check their journey times carefully, but it is a busy time of year."
On Saturday, passenger Rosie Pearson described the travel scenes in Dover as "carnage" as she was stuck for 16 hours with her husband and two teenagers.
Ms Pearson, 50, is an environmental campaigner from Essex and was travelling to Val d'Isere in the French Alps on an overnight bus.
The port said food and drink had been provided to coach passengers in the queues.
Shadow levelling up secretary Lisa Nandy said "a range of factors" have caused the delays, but she claimed the Government had not planned for what was going to happen post-Brexit.
She told Sophy Ridge On Sunday that ministers had "known for a very long time that they needed to make sure that there were resources in place to deal with additional paperwork checks".
She added: "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.
"I really feel for the families that are trying to get away for a Easter break, people who have been caught up in this chaos, people whose livelihoods are threatened.
"It didn't need to be this way.
"If the Government got a grip, got down to brass tacks and started doing their actual job, all these things could be avoided."
