Truck drivers will need a permit to enter Kent after the Brexit transition period ends, the government has said.
The announcement comes after a letter from cabinet minister Michael Gove warned that queues 7,000-trucks-long could clog up roads around the port of Dover and Channel Tunnel.
Speaking in the Commons, Mr. Gove said the Kent Access Permit system would be enforced by police and using cameras.
It is intended to ensure drivers have all the paperwork they need, he said.
Mr. Gove, the Chancellor of the Duchy of Lancaster, responsible for no-deal planning, wrote to logistics groups with the government's "reasonable worst-case scenario" planning for when the UK leaves the EU's single market and customs union rules on 1 January.
In that scenario, he said just half of the big businesses and 20% of small businesses would be ready for the strict application of new EU requirements at the border.
"In those circumstances that could mean between only 30% and 60% of laden HGVs would arrive at the border with the necessary formalities completed for the goods on board," he told MPs.
"They'd therefore be turned back by the French border authorities, clogging the Dover to Calais crossing."
He said it could lead to delays of up to two days for drivers waiting to cross the Channel. Although he said those queues were likely to subside after businesses learned from seeing their cargo denied access to the continent.
The transition period is due to expire at the end of the year but only a quarter of businesses are "fully ready" for the post-Brexit arrangements, Mr. Gove said.
Imports will also be disrupted in January, according to the letter sent to the freight industry by Mr Gove.
It also raises the prospect of a winter spike in Covid-19 leading to absences of port and border staff.
