Highways bosses have released a bullet-point list explaining why work to shift the moveable barrier on the M20 will take up to a year.

Drivers reacted angrily last week when KentOnline revealed how a 50mph limit, lane restrictions and nighttime closures will be brought back in between Junction 9 for Ashford and Junction 8 for Leeds Castle.

The barrier, which is used to form the Operation Brock contraflow system, will be moved from the London-bound hard shoulder to the central reservation amid safety concerns over its current location.

It was installed as part of Brexit measures to deal with potential disruption in the event of a no deal and has been stored at the side of the carriageway since December 2020.

But many have questioned why the relocation works, which are set to start next Friday, will take so long, with one councillor describing the timescale as "extraordinary".

Bosses say the project will be carried out in phases, starting at Junction 9 before "gradually moving" London-bound to Junction 8.

And in response to questions from KentOnline, National Highways has now issued a six-pronged list explaining what work will be carried out.

It says it will include:

1. Upgrading the central reservation to store the barrier

2. Permanent signage and posts

3. Permanent vehicle restraint system barrier

4. Upgrading an existing welfare area

5. Upgrading the drainage including the Junction 9 pond storage area

6. Upgrading the existing CCTV system

In a further statement, Nicky Potts, National Highways head of operational integration, said storing the barrier on the hard shoulder "was only a temporary measure".

"We are about to start work to move it onto the central reservation, its permanent home, which will allow the hard shoulder between Ashford and Maidstone to be re-instated to its original width," he said.

"This involves extensive construction work along the 13-mile stretch which will take up to a year. It will be carried out in phases, moving from Ashford to Maidstone.

"Road users will see the barrier in place on the London-bound M20, but it will be used as a safety barrier.

"If there is a reason to use the contraflow system as part of Operation Brock, it can still be easily deployed.

"I understand that this news will not be welcome by some people in Kent but we will do everything we can to minimise the impact on road users, and I ask them to please bear with us while we carry out this important work."

The first overnight closure between Junctions 8 and 9 will run from 8pm on Friday, January 28 to 6am on Saturday, January 29.

Bosses say they will be installing 'traffic management' during that time, with drivers advised to use the A20 as a diversion.

From Saturday, January 29 lane closures will be needed on both carriageways "for approximately 40 weeks".

On the London-bound side, the two outside lanes will be closed, with work starting at the Ashford end of the motorway.

The hard shoulder will be in use, so there will be two lanes running London-bound, and a 50mph speed restriction will be in place.

On the coastbound carriageway, the outside lane will be closed, but bosses say they will "aim to only close the section of road where work is taking place".

Earlier this week, Ashford MP Damian Green said he hadn't had a "satisfactory answer" from National Highways about why the works will take so long.

“I completely share people’s concerns,” he said.

“I can see the point of doing it if it makes it easier to deploy, because there will be less wasted time if it’s needed in the future, but why it takes 12 months I don’t know.”