A tugboat maneuvers the P&O ferry MS Pride of Kent, which ran aground in the harbour of the port of Calais on December 10 | Denis Charlet/AFP via Getty Images Northern France’s parallel Brexit talks Politicians and officials on either side of the Channel get together to tackle big border challenges.

PARIS — The French region with most to lose from Brexit is not just relying on Brussels for a good deal — it has taken matters into its own hands.

In Brexit negotiations running in parallel with the official EU-U.K. talks in Brussels, senior French politicians and civil servants have met repeatedly with high-level British counterparts to discuss the impact of Brexit on coastal economies and France's northern ports, according to French officials involved directly.

The goal is to avoid a deal that would harm regional economies on either side of the Channel by working out some issues away from the main Brexit negotiations, but also to make sure national politicians and the Brexit negotiating teams don't neglect their interests.

The Channel crossing is one of Europe's most heavily used trade thoroughfares, which will have to be repurposed entirely as a customs post by the time Britain formally leaves the EU.

It is a gargantuan task, one that French officials say dwarfs the cost and complexity of readying the Irish border for Brexit.

And yet, unlike Northern Ireland, the question of how to prepare the Channel and Calais for a post-Brexit reality has not yet featured in the official Brexit talks. That has left French and British officials scrambling to fill in the gaps before it is too late.

Xavier Bertrand, who is in charge of the vast Hauts-de-France region which encompasses Calais and the Channel crossing, has met with both EU chief negotiator Michel Barnier and French President Emmanuel Macron, pressing them to examine the Channel crossing question before Macron meets British Prime Minister Theresa May at a Franco-British summit in January.

The region set up a Brexit task force, bringing in regional, central, state and business actors starting last summer and has dispatched envoys to Britain to meet with counterparts at least three times, including a meeting between Karen Wheeler, director general for border coordination at Britain's Revenue and Customs service and Michel Lalande, prefect for Hauts-de-France. Bertrand held meetings in Dover with shipping representatives earlier this week and will meet Wheeler in January.

In another example of Franco-British rapprochement, from February, a contact group of 15 to 20 British and French MPs will start to meet on a regular basis to follow the border preparations and discuss how to safeguard coastal economies as Brexit unfolds.

Warmer tone

The tone of these interactions have been a good deal warmer than the main show in Brussels, according to a high-level British official.

"We're working on this together, so we can avoid getting bashed in the head with a situation that would be extremely painful" — Jean-Paul Mulot, Hauts-de-France region envoy to the U.K.

And the fact that many senior French officials — a list that includes Bertrand, Prime Minister Edouard Philippe, Foreign Minister Jean-Yves Le Drian, Budget Minister Gérald Darmanin and even, more distantly, Amiens-native Macron — have constituencies in northern France offers the potential that some of this goodwill might spread to Paris.

Jean-Paul Mulot, an envoy from Bertrand's Hauts-de-France region to the U.K., seconded the view that the northern French were instinctively more sympathetic to the British situation — up to a point.

"Obviously, a hard Brexit is going to penalize us [France] as well," he said. "We're working on this together, so we can avoid getting bashed in the head with a situation that would be extremely painful."

A desire to build common ground on Brexit was the reason Mulot invited British MPs to join a contact group, whose first meeting is scheduled for February, in France. He has also met business representatives in Britain, but unlike other Continental officials he said his goal is not to steal British business.

"That's seen as an attempt to destroy them. We have a different message," he said.

But at the heart of the outreach operation, is a thorny question: Which countries, between France, Britain and the EU27, will have to stump up the hundreds of millions of euros that it will cost to retrofit the Channel with customs infrastructure?

On the French side, they are arguing that the costs should be shared amongst the EU27. "We didn't ask for Brexit, so it's not up to us to shoulder all the costs. It's up to the states, and there should be a pro rata system for paying [for the border construction work]," said Mulot.

Unsurprisingly, the Brits are not keen to dip into their coffers for anything on the other side of the Channel. A U.K. government official described the idea of paying the French government to help them enforce the border as a "non-starter."

Preparing the border

The scale of the border preparations themselves — and the vital importance of getting them completed on time — is concentrating minds on both sides of the border.

Today, thousands of tons of goods travel by road or sea to Britain with minimal inspections. After Brexit, that is due to change, as customs agents will potentially have to inspect every container crossing the border. There may also be additional immigration checks for those coming in and out of Britain.

Vast parking lots, X-ray scanners and other technological tools will have to be built to accommodate the new checks. Dozens of new customs agents will have to be trained, with average training times around 18 months on the French side.

Mulot warned that "economic catastrophe" would befall not just the British and French economies, but that of all EU countries that export to Britain via the Channel if the negotiators fail to come to a deal on border arrangements.

The EU chief negotiator should expect more missives from Northern France before the Brexit talks are over.

"We need to be ahead of the game," he said. "There simply isn't the option of doing it at the last minute ... It's a question of economic survival."

With Phase 2 of the negotiations having received the green light from EU leaders last week, both sides of the parallel cross-Channel negotiations want to make sure their governments do not neglect their concerns.

Mulot said that Bertrand had told Barnier in a meeting last month that once the Brexit talks move to the second phase, "the Channel has to be right up next."

"Of course Barnier is running the negotiation," said Mulot. "But that doesn't mean we can't talk to him and give him info to make sure he's well aware of concerns specific to this area."

The EU chief negotiator should expect more missives from Northern France before the Brexit talks are over.