Holidaymakers waiting to cross the channel by shuttle have endured gridlock and delays of more than four hours on one of the busiest travel days of the year after "migrant activity" caused disruptions on the French side of the Tunnel.

Eurotunnel said people travelling to the continent from Folkestone faced a delay of an hour to check in and of 90 minutes at the terminal itself.

The operator was forced to suspend services last night because of what it called "migrant activity" in Calais, with reports that migrants were trying to break on to trains.

Those getting away at the start of the summer holidays have also been hit by Operation Stack, which closes the M20 in Kent coast-bound to cars between junctions 8 and 11 to hold waiting freight traffic.

Motorists vented their frustrations as they waited in lengthy queues this morning, posting photographs online as they sat in lines of traffic.

 

Le Shuttle, which takes passengers across the channel in cars, caravans, buses or other vehicles, usually operates up to four crossings an hour.

Journeys from France to London are running on time, with three departures an hour, but those leaving from Folkestone are facing delays of two-and-a-half hours.

The company tweeted: "Customers checking in late due to the travel disruption will be offered the next train with space available. Thank you for your patience."

Eurotunnel said it could not currently sell tickets to anyone who has not made a reservation, saying: "We sincerely apologise for the inconvenience this will cause to your journey."

Kent Police warned that Operation Stack, which holds freight traffic during disruptions to cross-Channel services, could remain in place until at least tomorrow.

Freight transport chiefs said Britain's freight industry is losing £750,000 a day because of the huge problems lorry drivers have faced this summer trying to cross the Channel.

Philip Gomm, of the RAC Foundation, said: "Kent is a major gateway to and from Europe but once again that gate is well and truly shut. Operation Stack has become the rule rather than the exception, and on one of the busiest travel weekends of the year it is causing mayhem for hauliers, holidaymakers and local residents alike."

He added: "Solving the immigration crisis is clearly a job for heads of government but that doesn't mean officials here can't do more to keep South East England moving. The depressing thing is that cross-channel disruption is nothing new and Operation Stack has been with us for almost 30 years. Yet only now are we seriously considering how to address its shortcomings."

Issues with migrants entering the Eurotunnel terminal at Coquelles have been a nightly occurrence in recent weeks.

There were delays to the service on Thursday when the body of a suspected migrant was found on the roof of a Eurotunnel train at the Chunnel terminal in Folkestone.

The news came as video footage emerged apparently showing migrants travelling to Britain on empty freight train carriages.

An estimated 5,000 migrants displaced from countries including Syria, Libya and Eritrea are now believed to be camped in and around Calais.