Part of the M20 is to close overnight as bosses prepare for the return of Operation Brock on Monday.

Both carriageways between Ashford and Maidstone are set to be closed at points this week to allow the hated contraflow system to be brought back.

Parts of the motorway between Junction 7 for Maidstone and Junction 9 for Ashford will be closed each night from tonight through to Sunday night as follows:

• 9pm tonight (Wednesday) to 6am Thursday (December 8): coastbound between Junctions 7 to 9

• 9pm Thursday 6am Friday (December 9): London-bound between Junctions 9 to 8
• 9pm Friday to 6am Saturday (December 10): coastbound between Junctions 7 to 9
• 9pm Sunday to 6am Monday (December 12): London-bound between Junctions 9 to 8 and the coastbound M20 between Junctions 7 to 9

When the carriageway reopens at 6am on Monday, the Operation Brock contraflow will be in place.

The altered road layout sees lorries heading to the coast use one side of the M20 while all other traffic is restricted to a contraflow system on the opposite side.

This means that motorists travelling this direction won't be delayed if there are large numbers of HGVs heading to the ports.

Lorries going to mainland Europe are legally required to follow the signed HGV routes to the Port of Dover and Eurotunnel when Brock is on.

Sean Martell, National Highways head of service delivery, said that bosses "understand this won't be welcome news for some" but insisted that the decision was down to "several factors" including expected high traffic numbers during the festive season.

"Ensuring the smooth flow of traffic through Kent is a top priority..."

“Ensuring the smooth flow of traffic through Kent is a top priority and we, along with our fellow Kent Resilience Forum partners, have taken the joint decision to activate the Operation Brock contraflow from the morning of Monday, December 12," he said.

"The crucial thing about the contraflow system is that it keeps Kent open and traffic moving in all but the most extreme circumstances. It’s also important that everyone follows the signs.

"Any HGV freight trying to jump the queue by using Brenley Corner will be turned back."

Operation Brock was removed at the beginning of September after being used over the summer, but the 50mph speed limit has remained in place due to work to widen the central reservation.

The middle of the motorway is being widened to allow the concrete barrier usually stored on the London-bound hard shoulder to be moved there.

The works will continue until next summer.