The government was warned that its plans under Operation Brock to use Manston as an emergency lorry park were “completely unsuitable” and risked businesses folding and prolonged gridlock on the roads, it has emerged.

The warnings were made by the leader of Dover council Kevin Morris and Charlie Elphicke MP in a letter to the then transport minister Chris Grayling.

The correspondence was released following a Freedom of Information request made by Kent Online.

The letter was sent on behalf of the Dover Task Force in March.

In it they raise a series of concerns about the impact of using the former airport site and cast doubt on the conclusions of a trial involving lorries being diverted there during Operation Brock, which would be rolled out in the event of a no-deal Brexit.

The letter says: “We are deeply concerned that not enough modelling has been done on driver behaviour. Their primary aim is to get from A to B as quickly as possible in order to deliver their goods on time. For many years their regular and preferred signed route will have been down the M20 to the Channel Ports.

"However, under the Operation Brock plans, freight drivers bound for Dover will be directed to Manston Airport.”

The letter goes on to question a trial run of the lorry diversion, saying the fact that only 89 of the 150 HGVs expected turned up was “a clear warning of what might happen in practise.”

It says there is no incentive to lorry drivers who will continue to queue on the M20 rather than be diverted to Manston.

It predicts Dover, Deal and Sandwich would “soon be completely cut off” with more traffic using rural roads to avoid the motorways.

And there could be a “severely damaging effect” on the local economy.

“With gridlock on the roads, companies will not be able to have vital goods and components delivered...for many businesses will grind to a halt.”

In his reply, the then transport minister Chris Grayling pointed out that the contingency plans “have been developed through extensive consultation over many months.”

He referred to a workshop exploring options that had concluded that the plan was “the most appropriate” in terms of the overall traffic impact for Kent.

But he said he fully understood the concerns about traffic disruption in the event Manston was called on under Operation Brock.

The scheme had been devised to cope with disruption “in a way that works for the whole of Kent,” he wrote.

Operation Brock sets out different phases to deal with congestion and delays, with Manston earmarked as an emergency lorry park capable of holding 6,000 to 8,000 lorries should there be no capacity on the M20 between Ashford and Maidstone.

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