More than 4,000 passengers arrived at Porstmouth ferry port on Sunday
An increase in foot passenger numbers because of the volcanic ash flight restrictions has been causing problems at Portsmouth ferry port.
On Saturday night police were called after a fight broke out between passengers who were frustrated by the long delays at passport control.
Brittany Ferries criticised the UK Border Agency (UKBA) saying it had too few passport control officers on duty.
The UKBA said: "The security of the UK border remains our chief priority."
Steven Tuckwell, from Brittany Ferries, said: "We have not been overwhelmed but certainly very busy - mainly [with] foot passengers returning from continent and lots of groups."
He said about 4,200 foot passengers as well as many people with cars and some freight arrived at Portsmouth on Sunday.
Many people had to queue for an hour at passport control and Mr Tuckwell said he thought people should have been allowed to show passports and get waved through.
"The problem is the ability of the port and particular immigration resources to be able to cope with the large numbers in such a short space of time," he said.
"The facilities for checking passports at Portsmouth port are geared to the normal flow of passengers and they were overwhelmed.
"The UKBA has been fully manned - there are four desks for foot passengers, given a couple of thousand passengers arriving in space of an hour it is clearly not enough."
He said two ships arrived at similar times on Saturday, leading to a "fracas" after some passengers tried to jump the queue.
"The report I had from our duty managers were that people were at the end of their tether," he said.
"The frustration at not being able to enter their home country was exacerbated by having to queue for a considerable amount of time."
A spokesman for the UK Border Agency said: "We are maintaining the security of the border and applying our normal checks and procedures to arriving passengers.
"We appreciate the situation faced by passengers and our aim is to deal with legitimate travellers as swiftly as possible.
"However the security of the UK border remains our chief priority."