About 100 people have been left stranded in Milan after an Easyjet flight to Manchester left without them.
They were due to depart on an Easyjet flight on Sunday but faced queues of up to three hours at Milan's Linate airport because of new border control checks.
Marooned passengers told the BBC people had been vomiting and passing out in the heat and now did not know how they would get home.
Easyjet said it was trying to support passengers but that the situation was "outside of our control".
One passenger, Kiera, 17, from Oldham, told the BBC she and her boyfriend faced a 20-hour wait in the airport until they could get another flight tomorrow.
She said it had cost her mother about £520 for new flights, but that they would be going to Gatwick, not Manchester.
She added: "We got here at seven-thirty for our flight at eleven so were super early.
"We got to Border Control and it was a massive queue of people. I wasn't feeling great anyway because I think I'd got food poisoning.
"At about ten-fifty they brought some water over for people, and when we got to the front of the queue someone asked us if we were going to Manchester, and told us our flight had just gone.
"There were only about 30 people got on the plane, and about 100 people didn't."
Student Kiera said when she emailed Easyjet to explain it was now going to cost her family hundreds of pounds to fly her to London and then pay for trains back to Greater Manchester, she was offered £12.25 in compensation.
"We won't be able to buy a sandwich at the airport for that, and we're going to be stuck here until we can fly tomorrow," she added.
'Blame'
Adam Lomas, 33, an accountant from Wakefield, was on holiday in Milan with his wife Katy, 31, and their four-month-old daughter.
He said: "We have been sat at the airport for hours. A few people have been on the phone to Easyjet.
"I attempted to contact them but just got chatbots and then there were audio issues and they couldn't hear me and after five or 10 minutes they hung up.
"We are trying to find a hotel and we are going to have to book a flight to London and then get from London to Manchester because our daughter's babyseat is there.
"We are just walking to a nearby hotel. Some passengers have driven to Pisa to fly.
"We thought it best to limit our movements because of the baby and so we waited around the airport for a long time before it became apparent that nothing was really happening.
"The airport and Easyjet have spent hours arguing with each other about who is to blame."
Easyjet said border delays caused by the implementation of the new European Entry / Exit System (EES) were "unacceptable".
The system - which was supposed to be brought in in October last year - became fully operational on 10 April.
The UK government warned people travelling to the European Schengen area that they might need to register their biometric details, such as fingerprints and photos, when they arrived on the continent.
It said people "do not need to take any action before they arrive at the border, and there is no cost for EES registration".
"EES registration is replacing the current system of manually stamping passports when visitors arrive in the EU.
"EES may take each passenger extra time to complete so be prepared to wait longer than usual at the border," it added.
A spokesman for Easyjet said: "We are aware that some passengers departing from Milan Linate today experienced longer than usual waiting times at passport control and we advised customers due to fly to allow additional time to make their way through the airport.
"We have been doing all possible to minimise the impact of the airport queues, holding flights to allow customers extra time and providing free flight transfers for any customers who may have missed their flight including EJU5420 to Manchester.
"We continue to urge border authorities to ensure they make full and effective use of the permitted flexibilities for as long as needed while European Entry / Exit System is implemented, to avoid these unacceptable border delays for our customers."
