The French government is starting a month-long Brexit dress rehearsal for trucks carrying goods across the Channel to Britain through the port of Calais.
"For one month we will act as if Brexit has happened," said Budget Minister Gerald Darmanin, who will launch the new customs system together with the British minister in charge of planning for a no-deal Brexit, Michael Gove.
"We will put in place a sort of dress rehearsal for most companies, in order to be fully ready at the end of October," Darmanin told RTL radio.
The French state has hired an additional 700 customs agents to cope with the border checks that will be put in place after Britain leaves the European Union.
Britain and EU members, particularly frontline states such as Ireland and France, are bracing for potential economic and travel chaos if, as is deemed increasingly likely, Britain crashes out of the union without a deal on October 31.
Darmanin attempted to assure the French that the situation was under control, thanks to the creation of a new "smart border" which will scan trucks' licence plates and automatically link them to shipping documents filled out online by exporters.
On arrival in Calais, trucks will either be waved through to take the Channel tunnel or a ferry to Britain, or be subjected to physical checks, depending on what type of goods they are carrying.
"You're a small business in Grenoble and you export to Britain: you declare everything online from now," Darmanin said.
"There will be bar codes and licence plate readers, and at the border -- unless there are checks because we think you are smuggling contraband or counterfeit goods -- your goods will go directly to Britain," he said.
There will not be "dozens and dozens of kilometres of queues in Calais," he promised.
In the event of a no-deal Brexit, trade between Britain and the EU will default to the World Trade Organization (WTO) tariff system.
Darmanin said it would be like doing business with South Africa, except that it would be "next door". He said around 100,000 French companies would be affected.