More than a hundred migrants were foiled as they attempted to gain access to a ferry bound for Britain in northern France yesterday.
Witnesses say the group were stopped from boarding a passenger ship by crew who raised the access ramp and shot a fire hose in their direction.
Video filmed by an onlooker shows a large group of people running towards a boat docked in Calais.
Truck driver Mark Salt, who recorded the footage while he was waiting to board the 17:15 crossing, told ITV News: "I heard a lot of other truckers banging their horns over by the check-in and Border Agency checkpoint.
"Then about 80-100 migrants came into view, heading straight for the ramps where a ship was about to dock.
"Several members of ferry staff and port workers (including Border Agency) attempted to corral these guys away from the ramps."
A spokesman for ferry company P&O told ITV News that the group had been trying to board a ship operated by MyFerryLink but crew on that boat managed to halt a "huge incursion" by raising their ramp and shooting a fire hose at the migrants.
A MyFerryLink spokesman said: "MyFerryLink can confirm that an incident took place in Calais yesterday, whereby several migrants entered the port and attempted to board the MyFerryLink Berlioz.
"The crew took immediate action to ensure the ship's security and the attempt was unsuccessful."
The P&O spokesman confirmed that the attempted incursion took place at 3.45pm on Tuesday.
The captain of the P&O boat coming into port witnessed the incident and held back from its docking to prevent becoming involved, the spokesman added.
A UK Border Force spokesperson said: "The ramps to the ferries were immediately raised when a number of migrants entered the port, and none of them were able to board.
"The incident was quickly brought under control and the French police apprehended all those involved.
"All freight vehicles inside the port at the time have been rescreened by Border Force.”
"Security at the UK border is our priority, and we continue to strengthen it to stop those who have no right to enter the UK."