Drivers are again enduring long waits amid the summer getaway chaos, with a huge section of the coastbound M20 shut to reduce congestion in Dover and delays to access Eurotunnel.

Last night, highways chiefs announced traffic heading towards the port would be unable to use the motorway between Junctions 8 at Maidstone and 12 for Folkestone.

Instead, motorists are being sent along a lengthy diversion using the A20, A249 and the M2 – while cross-Channel lorries must join the M20 Operation Brock queues, or risk a £300 fine. In the past 24 hours, more than 100 fixed penalty notices have been issued.

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

But by 7am, there were already long delays on diversion routes and this afternoon frustration is growing as vehicles trying to access Eurotunnel off the London-bound M20 have been at a virtual standstill for hours.

P&O Ferries says the A2 queues stretch beyond the junction with the A256, with traffic taking as long two hours to reach the port.

It stresses the A20 in Dover is also blocked, with delays of up to 45 minutes. "Once you reach the port, the wait time is approximately 90 minutes to two hours to reach border checks," the ferry firm added.

Speaking during a whistle-stop tour of the county today, Foreign Secretary Liz Truss joined the furore by blaming French authorities for causing the delays.

The senior Conservative said: "The fact is the French authorities have not put enough people on the border.

"I'm in touch with the French authorities and I'm very clear that we need to see action from them to resolve the terrible situation people are facing."

The Foreign Secretary, who is the bookies' favourite to become the next Prime Minister, downplayed concerns the issues were a result of Brexit.

Ms Truss insisted: "This has been caused by a lack of resource at the border. That is what the French authorities need to address, and that is what I've been very clear about."

People living along the A20 corridor have also reported congestion.

Resident Rose Anderson warned: "If you're trying to travel today traffic is gridlocked on Horn Street, Cheriton High Street and further back, but it's right up to the Cheriton island for the Eurotunnel.

"I just feel sorry for people who are actually stuck in the queues, especially with the heat."

Motorists are stuck in queues on the London-bound M20 which had been blocked by people waiting to access Eurotunnel services.

One of them, Anna McCrum, said: "We have been stuck by the Eurotunnel terminal for five hours. We have moved about 100m in that time. We've missed our crossing and no idea how long we will be here."

Gordie and Lynne Pearson, from Chatham, were trying to get home after spending an evening in Folkestone to celebrate their 50th wedding anniversary.

"We spent four hours on the slip-road," said 69-year-old Gordie. "It was a nightmare. In the end we cut across the grass to get on the motorway.

"It was blocked up right back into the middle of the town because of people waiting to get to the Channel Tunnel.

"In four hours, we moved about 400 yards. It was just rammed.

"I'm pretty sure there's going to be fisticuffs soon. There were a couple of altercations on the slip-road, with people getting ratty."

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

The M20 coastbound closure to non-freight traffic was extended overnight, having originally been between just Junctions 8 and 9.

A National Highways spokesman said: "The M20 is closed for non-freight traffic coastbound between Junction 8 (Maidstone) and Junction 12 (Folkestone) to manage HGVs and other freight heading for the Port of Dover or Eurotunnel as part of Operation Brock.

"The M20 eastbound entry slip roads at Junctions 9, 10 and 11 are closed to help manage traffic flows.

"Road users are advised to expect delays on the M20 eastbound on the approach to Maidstone as a result of the closure.

"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 the county 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 warned 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 yesterday they faced 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 yesterday morning.

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

The row continued today, with Dover MP Natalie Elphicke saying the French should say sorry.

"They should apologise to Dover residents and holiday makers for the unnecessary holiday chaos at the start of the summer getaway," the Tory said.

In a video posted online she said it was time to end "this sticking plaster approach".

She called for urgent investment in long-term solutions to allow the port to grow and boost the county's economy.

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

Port of Dover CEO Doug Bannister said the border controls were "insufficiently resourced" and advised drivers to avoid travelling to the town.

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

The Kent Resilience Forum (KRF) said it was working hard to keep traffic moving to support those living, working, visiting or passing through the county.

In a statement released this afternoon, Toby Howe, KRF tactical lead said: "We’re very aware of the impacts of border disruption and currently using traffic controls are our best option for keeping the county moving as smoothly as possible.

"We thank everyone for their ongoing patience and are committed to helping everyone overcome these issues but due to the disruption being experienced at the ferry ports and Eurotunnel it is important that drivers should plan for lengthy delays and ensure passengers having ample supplies of water, food or any medicines needed.

"Drivers should also check vehicles before setting off to ensure there are no issues with tyres, oil or fuel.

"The KRF continues to do everything it can to get the queues reduced and people on their way. Please don’t leave your safety to chance – if you decide to travel, you must be prepared."