Work has started to enable a motorway to be turned into a car park to deal with a no-deal Brexit.
On Wednesday night Highways England began preparations for the M26 in Kent to be used as a holding area for lorries if there is gridlock.
There is concern there could be delays at the nearby port of Dover if the UK withdraws from the EU without an agreement.
There will be overnight closures on the motorway until Monday and in the run up to Christmas between November 19 and December 21 while the work is carried out.
Diversions will be in place via the M25 and M20.
A plan called Operation Brock will also see traffic able to park on the nearby M20.
Sections of the M20 are currently closed under Operation Stack when lorries are forced to queue because of disruption to rail or ferry services, causing chaos for local journeys.
Tom Tugendhat, Tory MP for Tonbridge and Malling, said his community was kept in the dark about the M26 work after receiving assurances that nothing was planned.
Transport Secretary Chris Grayling said he did not expect any of the no-deal Brexit contingencies to be required as he believes a deal will be struck with Brussels.
Speaking in the Commons, Mr Tugendhat said: "It's come to a pretty pass when a member finds out that works have begun on a motorway to turn that motorway into a parking lot without consultation either with the local community or with surrounding members.
"The M26 works started last night. I wrote to (Mr Grayling) in April asking whether or not this would happen.
"I was assured the works were not planned and only yesterday was it confirmed to me that Highways England had said that is exactly what was planned, despite having told me the reverse a week earlier."
He urged Mr Grayling to explain how the planning permission was granted with "no consultation".
Mr Grayling said he was happy to meet Mr Tugendhat to discuss the issue, adding: "I do not expect any of the contingencies that we have in place for a no-deal Brexit to be needed because I'm confident we will reach a sensible agreement."
A spokesman for Highways England said: "As part of wider resilience planning, Highways England has been asked by the Department for Transport to develop plans to utilise the M26 to hold heavy goods vehicles, should further capacity be required in the future.
"We will be undertaking site surveys on the M26 during October leading to the installation of two gates in the central reservation to support the safe management of freight in the future, if needed."