On Monday (March 4), around 40 customs officers working in Calais (Pas-de-Calais) and Dunkirk (Nord) decided to “demonstrate what is going to happen” when the United Kingdom is no longer part of the European Union after March 29.

The officers said they were motivated by worry and anger over the still-unsure Brexit situation, and wanted to use the strike as a way to denounce this lack of preparation in case of a no-deal.

The “strike” - called for by unions CGT and Unsa - saw officers impose stricter controls, applying “to the letter” the regulations that will become necessary once Britain is out of the EU.

This caused many heavy goods vehicles to become queued up on the roads leading to the ports, causing several kilometers of traffic jams on the A16 and A26 roads towards the entrance of Eurotunnel and towards the ferry terminals.

Authorities later imposed “stacking” areas for lorries, in an attempt to regulate traffic.

Individual cars and vehicles were able to circulate normally.

David-Olivier Caron, general secretary of border union CFDT-Douanes, said: “Agents are imposing a strict application of the regulations, and are doing stricter checks...Brexit will be a catalyst of a deeper malaise; [increasing] the difficulty of our work and the danger of our mission.”

The strike quickly caught the attention of public accounts minister Gérald Darmanin, who received union representatives to discuss the issue.

The French government has already announced that it will recruit seven extra border agents post-Brexit to ease the situation, but union heads say that this will not be enough.

Currently, around 300 officers work at the Calais Eurotunnel border, and around 60 work at the Port of Dunkirk.

CGT representative Philippe Bollengier said: “If Great Britain becomes a third party country, there will be more extensive checks. Today, we have clearly demonstrated what is going to happen. We estimate that the extra labour from [just] seven agents across the whole of France will not be enough.”

Vincent Thomazo, general secretary of Unsa-Douanes, said: “[The government] is asking a huge effort from us; it will be a huge effort to re-install the border with very few extra resources.”

Unions were also protesting the lack of training given to existing border officers on the extra new procedures that will be required.

Officers submitted a collection of grievances on the matter to their regional directors on February 22, but so far say they have received no response.