More traffic misery will be piled on motorists this weekend as they face having to endure a huge M20 diversion towards the coast.

Highways chiefs have announced traffic heading towards Dover will be unable to use the route between Junctions 8 for Leeds and 9 for Ashford from tonight.

Drivers will be sent along a lengthy diversion route using the A20 before rejoining the motorway near Hythe – while hauliers will join the stretch's Operation Brock queues.

Officials believe the measures will help combat the cross-Channel travel mayhem at the Port of Dover by "reducing disruption" across Kent.

A National Highways spokesman said: "We will implement a closure for all traffic on the M20 coastbound carriageway between J8-9 to ensure EU-bound lorries use Operation Brock.

"All other coastbound traffic will be diverted off the M20 o re-join it at Junction 11.

"These additional measures will be introduced immediately and will result in longer journeys but will help keep traffic moving.

"All drivers planning to travel in or through Kent should plan ahead, follow diversion signs, check before they travel and leave plenty of extra time for their journey."

The spokesman stresses the measures will be kept under review.

He also warns anyone travelling to the Port of Dover or Eurotunnel "should pack some food and water in case they are delayed".

This comes after motorists queuing for the port were told earlier today they face waits of more than four hours due to issues with French border control.

French authorities have pointed the finger at an unexpected "technical issue" in the Channel Tunnel, insisting it delayed their border police teams from deploying in Kent this morning.

But Eurotunnel bosses state "that is absolutely not the case", and that the problems started "well before" the glitch.

A critical incident was declared this morning as the border confusion gridlocked Dover, leaving residents unable to get to work and children stuck on school buses.

The port officials have since announced "traffic is slowly beginning to move" and "will take some time to clear the backlog".

Its CEO, Doug Bannister, told KentOnline: "We have a lot of congestion that is trapped around on the road ways.

"Right now we're focussing on getting people travelling.

"That's our main area of purpose right now. And after that we'll focus on what went wrong with resourcing levels."

Declaring a critical incident this morning, Mr Bannister said the border controls are "insufficiently resourced" and advised driver to avoid on travelling to the town.

This evening, there remain delays of up to five hours at the Eurotunnel near Folkestone due to exceptionally high demand, with tourists trying to use the service instead of the port.