Long queues of lorries have formed three weeks before the UK's exit from the European Union, with a post-Brexit trade agreement still being discussed.
Ports in France and the UK are gridlocked as businesses scramble to stock-up, while some British retailers have expressed concern they'll struggle to get products into stores.
"There is a lot of anticipation about Brexit on the British side," said Sebastien Rivera, Secretary-General of the National Federation of Road Transport.
"They are in the process of setting up warehouses in anticipation of the additional steps involved in Brexit; customs declarations, security declarations, and customs duties. Goods are likely to cost more.
"For the last 3 weeks, we have seen an increase in the stock flows to the UK. Places like the port and the tunnel, are not able to cope with this increase."
France is the UK's gateway to Europe. In 2019, 3.4 million lorries crossed the Channel and a train also runs through the tunnel linking the two countries every 3 minutes.
In total, 30 million passengers cross the border between France and the UK every year.
The Gare du Nord in Paris, which is connected to London's St Pancras station by the Eurostar, is preparing for the change, according to France's public action and accounts ministerOlivier Dussopt.
'We have recruited 600 additional customs officers to deal with Brexit, and of these 600 officers, some of them are posted here (at Gare du Nord).
"From January 1, Gare du Nord will become an exit point from the European Union, an exit point from the internal market.
"Great Britain becomes a separate country, it means checks, air and border police controls with people needing a passport to cross this border."
The end of the Brexit transition period looms large on December 31, when ravel and trade protocols between France and the UK will change.
What a post-Brexit trade deal between Britain and the EU will look like remains up in the air.