The government has been warned it is facing a race against time to be ready to implement Operation Brock on the M20 ahead of Brexit.

And industry experts say questions remain over plans for frictionless trade because the number of so-called trusted traders in the UK remained small.

A cross-party committee of peers examining the impact of Brexit on transport in the UK was told the government’s contingency plans to manage traffic on the M20 depended on a number of different factors coming together ahead of March 29.

Andrew Meaney, of the transport consultancy Oxera, told the inquiry: “We know where the project has got to from a Highways England perspective.

"There is a lot of operational detail that needs to be finalised between now and the end of March, let alone putting in the contra-flow infrastructure, the signage, the training of the people who are going to make all this work, and then you need a substantial information exercise for people coming in from places like Poland, and lorries going out. So there are a lot of things that need to be put in place.”

“This is an issue that ports in mainland Europe is concerned about.”

Alan Braithwaite, of the Chartered Institute of Logistics and Freight (CILT) said the risk of congestion at Dover could be affected because relatively few UK companies were seeking “trusted trader” status.

This allows them to be fast-tracked through customs.

He told peers that the concept was integral to the Chequers deal but that the likelihood of speedier customs checks was limited in view of the number of businesses that had applied to be designated.

“At the moment, there are about 600 authorised traders in the UK and 5,000 in Germany. So, we are not ready. We are very concerned that British industry has not grasped that this is an essential precondition of frictionless trade and we have asked the DfT and other agencies to promote this.”

Mr Meaney echoed: “There are 300 lorries moving through the Port of Dover per hour per day; at the moment, nine of those are checked. If the government wants frictionless trade how many of the 2,91 HGVs are you going to check? The ports on the other side [of the channel] are equally concerned.”

Alan Braithwate said at any one time, half of the haulage traffic moving through Dover was carrying food.

“You can put this stuff [perishable food] into other ports but it is going to be more expensive for the port operators and hauliers and those costs are going to find their way into the supply chain and into consumer pockets.”

The warnings follow a claim by the boss of Jaguar Rover Ralf Speth that it faced losses of £60m a day under a hard Brexit. He said traffic jams on the approach to Dover meant that “bluntly, we will not be able to build cars”.

The DfT is expected to set out further details on its plans for Operation Brock later this year. Recently released reports suggest it could lead to a 13-mile lorry park on the M20 that could last “many years" after Brexit.

The initial wave of works on the £20 million scheme have begun with hard shoulders being reinforced to sustain hundreds of parked lorries between Ashford and Maidstone