The government is facing criticism after it refused to release details of any contingency plans it had drawn up to cope with possible disruption to Kent’s road network after Brexit.

The Department for Transport ruled it would not be in the public interest for details of any of its plans to be put into the public domain.

It has rejected a Freedom of Information request by Kent Business for details of any proposals to mitigate the impact of Brexit in 2019 should the UK leave without a deal.

The DfT said that while it had information about contingency measures, it was not prepared to release it because to do so might damage the government’s negotiations at “this sensitive stage of the department’s planning for exiting the EU”.

It added that policy was still under development and early release could confuse or mislead the public.

The Road Haulage Association said it was concerned its members would not have information in time to prepare their own contingency plans.

Despite this refusal, the Transport Secretary Chris Grayling let slip the site of the former Manston airport in Thanet is likely to be retained as an emergency lorry park in the event that Operation Stack is implemented after Brexit.

He said: “We have the whole of Manston airfield available to use if Operation Stack is needed when the Channel ports don’t function.

“We’re now doing detailed work to look at how we take those arrangements forward in 2019 if we need them.

“We have got contingency plans in place for delays around the lorry ports right now but what we’re working on is making sure we’ve got developed plans for 2019. We will have those in place.”

Kent County Council’s Cllr Matthew Balfour, of the Kent Freight Transport group, said he would be writing to Mr Grayling to seek clarity over the government contingency plans.

He said: “Freight fluidity is essential to the operation of the port and the Kent and UK economy.

“The group is concerned that without confirmation of what customs arrangements will look like after Brexit, both the EU and UK ports could potentially not be ready to cope with the increased customs checks required.

“What we do not want is a repeat of the disruptions of 2015 when Operation Stack was in place for 32 days.”