Tourists who drive to the Continent face chaos at Dover unless a deal is reached with the European Union over new border rules coming into force this year.
The warning came from the boss of the Port of Dover, who urged ministers to seek a deal with Brussels which could make the checks less intrusive.
Doug Bannister warned of potentially 'significant' tailbacks for tourists and hauliers when the new rules come into force in October.
Because the new system will require biometric checks, it would mean every car and lorry passenger having to exit their vehicle. This would mean border crossings taking much longer, causing lengthy queues.
As it stands, tourists who drive through ports to the Continent can simply have their passports assessed and stamped by border guards through their vehicle window, keeping traffic flowing smoothly.
Lorries queue for the Port of Dover in Kent on January 18, 2022
To handle the new checks Dover would also need new infrastructure.
But the European Union is yet to clarify the finer details of the policy, known as the 'entry-exit system', and the extent of the checks needed.
No technology currently exists which could scan the face, passport and biometric data such as fingerprints of each passenger while remaining in their vehicle.
Mr Bannister told the Mail: 'We have nine months to design a process to identify and implement technology and come up with a regulation that works, and invest in any infrastructure and other investments that we need to.
'It feels a very short period of time to get that all done.
'It probably could get done, but what needs to unlock is the UK government speaking directly with French counterparts and wider in the European Union about how we're going to create a solution for this.'
He added: 'If there isn't a solution, we could well wind up having significant queues for both tourists and freight.
'There's no solution, no process, nothing that's been designed for a car load of people going through a busy ferry terminal on a dark night. It doesn't exist. We need a solution identified, we need the technology and the process to be discussed and then we need time to be able to implement all that. September feels awfully close for all that to happen.
