The coastbound M20 was closed between Junctions 8 and 9 after Operation Stack was brought in.

Congestion mounted as strike action in France led to serious delays at the port of Dover.

The 24-hour industrial action at the Port of Calais was expected to last until 7am on Friday but finished in the early hours of the morning with Stack stood down as a result.

The Coast bound entry slips roads between J8 and J13 had been closed and queues on the motorway were as far back as Junction 7 for Maidstone and Detling Hill by mid-afternoon.

Non-freight traffic was diverted onto the A20, where Dover TAP was in place until 2.30pm.

Queues also backed up on the M2 Eastbound, with a 30-minute delay building between J5 for Sittingbourne and J7 for the A2, due to traffic diverting from the M20.

It is only eight days since Stack was last implemented, after counter terror operations caused mass delays at the port and at Eurotunnel.

Dover and Deal MP Natalie Elphicke said: “Last week Dover went into gridlock when there were delays putting its traffic management systems in place quickly.

"I am pleased to see that lessons were learned from last week and that Operation Stack was stepped up today quickly in response to French industrial action.

"These traffic management systems are vital to Keep Dover Clear so that local residents can get out and about to work, to go to school, shops and access healthcare.

“As we move forward to the end of the year, traffic and border controls will step up a gear.

"I have been working closely with the Cabinet Minister, Michael Gove, and the Transition Roads Minister, Rachel Maclean, to ensure that plans to Keep Dover Clear are an important part of transition planning.

"If lorries and port traffic follow the rules and stick to the traffic plans when there is disruption – whether from security alerts, French strikes or leaving the EU – their cross-channel journey will be all the smoother and quicker, and they will be playing their part to Keep Dover Clear for residents.”

P&O Ferries tweeted that its services were suspended and the firm was arranging for other providers to take its customers across the channel.

DFDS was still operating to and from Dunkirk and passengers were able to transfer onto one of those sailings.

A Port of Dover spokesman said: "Due to the ongoing period of industrial action in France which commenced at 07:00 hrs today, the Port of Calais remains closed to shipping.

"Ferry services to and from the Port of Dover are therefore still affected.

"Freight traffic heading to France continues to build up and the implementation of Operation Stack (holding freight on the coast-bound carriageway of the M20) is now probable.

"We are liaising closely with Kent Police.

"The is open and tourist traffic bound for Dover is advised to use the M2/A2 route."

For a full explanation of Operation Stack and how it works, click here

Read more: All the latest news from Dover