The plan, codenamed “Operation Brock”, was announced formally to Parliament on Monday and is to be delivered in time for Brexit Day next year.
Though the Government denies any direct connection with Brexit, this interim solution was earmarked for delivery before any possible change to customs arrangements in March 2019.
It followed the likely loss of a judicial review into the Government’s favoured permanent successor to “Operation Stack”.
The coastbound section of the M20 between Junction 8 near Maidstone and Junction 9 near Ashford will be earmarked to hold Heavy Goods Vehicles, in what will effectively become a giant temporary lorry park.
The London-bound stretch will then become a contraflow with two lanes of cars going each way.
Highways England will spend £25m on these preparations, including the purchase of several tens of thousands of cones, and the hardening of both the hard shoulders to cope with normal traffic.
A Government source said that “this would be needed regardless of Brexit” and pointed out that a repetition of Operation Stack had been avoided on several occasions.
This arrangement should allow normal vehicle traffic to continue to flow in Kent even if there is cross-Channel disruption.
The Government also acknowledges a structural shortage of lorry parking spaces, and will open a consultation on longer term solutions to the problems of lorry traffic gridlock.
Such a long term solution is not expected for a few years, and does depend on the post-Brexit customs arrangements reached with the European Union.
Stephen Doughty, a Labour MP campaigning for a “People’s Vote” on the Brexit deal, said the move showed that “Brexit threatens to make 30-mile queues a daily reality”.
“The Government is beginning contingency planning for traffic delays due to customs hold-ups, which means they are fully aware of the logistical nightmare they are going to cause through their ludicrous decision to leave the Customs Union,” he said.
“No-one voted for a Brexit that results in traffic chaos around our ports and airports.”