Summer travel plans risk being thrown into chaos for British holidaymakers after airport and ferry operators warned that new EU border controls are causing lengthy delays.The EU recently completed the rollout of its Entry-Exit System (EES), which requires travellers from outside the bloc to register biometric information when entering most European countries before it is checked again on departure.While the system has operated smoothly in some countries, it has also caused significant hold-ups at several airports.The president of Airports Council International (ACI) Europe, Stefan Schulte, said politicians should 'stop pretending... that EES is working just fine. It is not.'Speaking at an event in Prague, Schulte said: 'Passengers are queueing for hours at peak traffic times and I just do not know how we will be able to cope in the coming weeks with the expected increase in traffic.'He added that the EES should be suspended by Border Force when needed to avoid chaos, adding that 'this is about showing respect and decency for those who chose to travel to the EU, and safeguarding our reputation as a welcoming and efficient destination.'Christophe Mathieu, chief executive of Brittany Ferries, said the company shared airlines' concerns about the rollout of the EES and was worried by the way it was being introduced.Speaking on BBC Radio 4 on Wednesday morning, he said that what Brittany Ferries had seen so far was troubling, because it increased the time needed to leave the port by around 50 per cent. While the system has operated smoothly in some countries, it has also caused significant hold-ups at several airports The EU recently completed the rollout of its Entry-Exit System (EES), which requires travellers from outside the bloc to register biometric informationHe argued that the run-up to summer was not the right moment to be finalising a system that should already have been tested and fully in place.Mathieu said the rollout would come as an unwelcome surprise for tourists and that Brittany Ferries had repeatedly raised its concerns with authorities in Paris, Brussels and Madrid over the way the EES was being implemented. Although officials had said they were working on the issue, he suggested there appeared to be a disconnect between those assurances and the reality on the ground.He said Brittany Ferries believed there was a practical solution, suggesting that fingerprint and facial checks could be carried out during ferry crossings, with customs or border force staff operating booths on board, allowing passengers to disembark seamlessly on arrival at port. He said the company had put forward the idea, but it had so far failed to gain traction.The disruption is already visible, as earlier this month, a Ryanair flight heading to the UK from Greece took off without dozens of its passengers on board due to 'mega queues' at passport control.Authorities at Athens International Airport were forced to step in after 20 to 50 travellers booked onto the flight to London Luton were left stranded on Sunday.Ryanair blamed border delays for the chaos, while the airport said it had been experiencing congestion linked to the introduction of the EES.Milo Boyd, a travel writer, said there was a 'mega queue' of several hundred people at both the airport's security checks and passport control.He and his wife managed to make it through just ten minutes before the gate closed, but he said furious passengers were pleading with Ryanair to let them on the flight.And it is not the first time travellers have missed their flights as a result of chaotic airport queues.British airline passengers were recently left behind in Toulouse after a plane took off without 150 of its passengers on board.Passengers were unable to reach their gate in time for flight FR282 to London Stansted on May 30.One woman travelling on the plane said the situation in the airport was 'pure chaos', with delays beginning after security.The passenger said around 400 or 500 people were all queueing in this area, and there was no real organisational system in place.Meanwhile, a Ryanair flight from Milan Bergamo to Manchester took off on April 16 without a number of its passengers on board. Vehicles queue to enter Greece at the Evzoni border crossing Travellers at Toulouse airport were stuck in long queues on May 30, meaning around 150 missed their flight to the UK (image supplied to The Connexion)Adam Hassanjee, 18, from Bolton - who was one of the stranded passengers - told the BBC: 'We were waiting for an hour and a half and weren't moving.'Then we see the plane leave and got told we have to go and book our own flight back.'Reports suggest around 30 people were left stranded, although Ryanair did not confirm exact numbers.The European Commission is now allowing EES to be suspended in some circumstances until September. And earlier this year, Greece's tourism minister Olga Kefalogianni said she did not want tourists to be 'burdened' by bureaucratic procedures when entering or leaving Greece.Kefalogianni promised British passengers would not face biometric checks when travelling to the country, however the situation remains unclear after the Greek Foreign Ministry later disputed that any exemption existed.