The CEO of the Port of Dover has warned the port could face "significant and continued disruption for a very long time" post-Brexit.
Doug Bannister has told MPs he has been invited to Calais, France to view tests for the European Union's incoming Entry/Exit System (EES).
He said the port has not been given any details of the scheme's rules but expressed concern it could cause "significant and continued disruption for a very long time" following its planned introduction in May 2023.
It is expected to involve travellers from non-EU countries such the UK having their fingerprints scanned and a photograph taken to register them onto a database the first time they enter a member state.
The system is a key part of the UK's post-Brexit relationship with the EU, and will determine how smoothly travel to the bloc will be in the future.
Over the past year there have been huge queues snaking miles out of Dover, despite many Tory MPs such as Jacob Rees-Mogg insisting there would be no issues at the port if the UK voted to leave.
“We will maintain a free-flowing border at Dover," he said during the campaign. "The delays will not be at Dover, they will be at Calais."
This week Mr Bannister was asked by the Commons' Transport Select Committee what passengers will need to do under the new system. He explained that officials would be visiting Calais in coming weeks, but didn't have a firm answer.
However he did warn: "It's going to have a higher impact on families wishing to go abroad next summer."
He told the committee that processes hadn't yet been seen, but expressed concerns that processing a car could jump up from 90 seconds to 10 minutes.
He added: "We need to know what the rules of the game are. We need to see what the technology is going to be, we need a sufficient amount of time to trial, test and train to use that technology before implementation."
Tens of thousands of families saw their holiday plans ruined in July due to miles of gridlocked traffic around the Kent port.
This was blamed on a lack of French border police.
Asked what steps have been taken to avoid a chaos returning, Mr Bannister told MPs: "What we anticipate is that we would have an earlier warning if they are unable to man to appropriate resource levels.
"Then we can enact any of the contingency plans on our side to try and do the traffic management."