More than 35,000 people passed through the port on Friday with more expected over the course of this weekend, officials said.

A nine-lane-wide queue stretched alongside the white cliffs during Saturday morning on the approach to the border where French guards were checking passports.

An ambulance flashing blue lights was temporarily stuck in traffic before making it through.

Despite the delays, authorities warned travellers not to arrive more than three hours before their sail time.

At 7am, they said in a statement: "The current average processing time through to the border is 120 minutes, as per our peak travel plan for the busiest times.

"Rest assured, you will be on the next available sailing upon reaching check in."

By 9.30am, officials said the wait time had been reduced to between 90 to 120 minutes and that travellers must pass through border checks before boarding their ferry.

Travellers have been urged to use main routes only to avoid further traffic delays, with officials saying: "This morning is one of our most popular times of travel throughout the summer."

Google Maps showed slow traffic all along the A20 almost as far as Folkestone.