The M20 has been branded the UK's slowest motorway.

MP Charlie Elphicke says this is because of a series of speed restrictions including from Operation Brock, which began on March 25.

Steel barriers were put up between Junctions 8 and 9 London-bound, Ashford to Maidstone, for the Operation Stack replacement.

This is so traffic can flow in both directions when there are delays at the Channel ports.

But it means another large section of the M20 has a reduced speed limit, the Dover MP says.

Junction 10 at Ashford already has a 50mph limit because of roadworks to complete the new Junction 10A.

Meanwhile Junctions 3 to 5, Sevenoaks to Aylesford, has one during upgrades to become a smart motorway.

Both projects are due to be completed in 2020.

In recent days a decision was made to deactivate Operation Brock by returning the 70mph limit on the three coastbound lanes.

But the steel barriers on the London-bound side, including the 50mph limit, will remain in place.

Mr Elphicke said: “Residents are furious. Operation Brock is not a solution.

“It means yet another section of our motorway has a reduced speed limit. The M20 now has to be the slowest motorway in the country.

“The most frustrating part is there are solutions and they are simple.

"We need long-term investment – in things like lorry parks and a dualled A2.

“This had been needed for years. If we just got on with it, we wouldn’t need these bizarre, go-slow traffic schemes.”

In recent weeks Mr Elphicke arranged for a joint letter from all east Kent MPs and council leaders to ministers at the Department for Transport.

It asked them to provide funding for a feasibility study to dual the A2 to the Port of Dover, and for the scheme to be included in the next Road Investment Strategy.

Mr Elphicke is due to have talks with roads minister in the coming weeks.

He also criticised the decision to use Manston Airport as part of the new Operation Brock.

He added: “It’s a bad idea. Manston is a long way from the port – while lorries will have to thunder down single-lane roads to get there.

“We have been making these points for months. We need to see action – because people are fed up."

A Highways England spokesman said: "The improvements we are making along the M20 will bring real benefits for drivers in Kent by adding an extra lane in both directions at Maidstone and creating a new junction at Ashford.

"The Operation Brock barrier brings benefits too by providing an alternative to Operation Stack that can keep the motorway open in both directions if there is disruption at Dover.

"We are grateful for people's patience while we deliver these upgrades and are working hard to keep disruption to a minimum."

The spokesman added that England's motorways and major roads are 99% free of roadworks this Easter.

Highways England explains that two lanes and a 50mph speed limit remain in place on the London-bound carriageway in case Operation Brock needs to be re-activated again in the coming weeks.

It adds that reopening the third lane now would slow down the quick implementation of Operation Brock if it is needed.

It would require repositioning the steel barrier, which is fixed to the road surface.

The barrier is also positioned to direct traffic to cross over the coastbound carriageway at each end.

Highways England adds that there are also gaps in the central reservation barrier at each of the crossover points. Running traffic on both sides of it would carry a risk of vehicles crossing over into the path of oncoming traffic.

Finally, the agency says that the barrier takes about four weeks to put up and that time to take down.

It says it and its partners would have to he sure no disruption is expected over this time to be able remove the barrier completely.