France seized a British trawler fishing in its territorial waters without a license on Thursday and issued a warning to a second vessel in a dispute over access to fishing grounds after Brexit.
Furious that Britain has refused to grant its fishermen the full number of licenses to operate inside British waters that France says is warranted, Paris announced retaliatory measures on Wednesday if there was no progress in talks.
The French government said it would from Nov. 2 impose extra customs checks on British goods entering France, raising the prospect of more economic pain before Christmas for Britain, which faces labor shortages and rising energy prices.
It is also reviewing a second round of sanctions and does not exclude a review of its exports of electricity to Britain, which left the European Union on Jan. 31, 2020.
"It's not war, but it is a fight," France's Seas Minister Annick Girardin told RTL radio.
European Affairs Minister Clement Beaune signaled France would be forceful in the dispute.
"So now, we need to speak the language of strength since that seems to be the only thing this British government understands," Beaune told news channel CNews.
British Prime Minister Boris Johnson's office did not immediately respond to a request for comment on the detained trawler.
Britain has said France's planned acts of retaliation will be met with an appropriate and calibrated response.
"France's threats are disappointing and disproportionate and not what we would expect from a close ally and partner," a British government spokesperson said.
Barrie Deas, head of Britain's National Federation of Fishermen's Organizations, said Britain was issuing licenses in line with the terms of the post-Brexit trade agreement and that France appeared determined to escalate the license row.
"I suppose we have to wonder why. There is a presidential election coming up in France and I think all the signs are that the rhetoric has been ramped up ahead of that on the fishing issue," Deas told the BBC.
French President Emmanuel Macron has not yet confirmed he will seek a second term in April's election but is widely expected to run.
French maritime gendarmes made multiple checks on fishing vessels off the northern French port of Le Havre overnight, the Maritime Ministry said, as France steps up surveillance during negotiations.
The seized trawler, now under the control of French judicial authorities, had been rerouted to Le Havre under a maritime police escort and was tied up on the port's quayside.
The vessel's captain could face criminal charges, with his catch confiscated, the ministry added.
The Marine Traffic app showed a British fishing vessel named Cornelis Gert Jan tied up in the port of Le Havre. The French maritime patrol vessel Atos was moored behind it.
Reuters could not immediately confirm the name of the detained vessel.
Marine Traffic data showed that the Cornelis Gert Jan had been operating in the Baie de Seine on Wednesday evening, where the Atos had been conducting checks. Both vessels set course for Le Havre at around 2000 CET (1800 GMT).
Britain has said it issued fishing licenses to vessels able to show a track record of operating in its waters in the years prior to its withdrawal from the EU.
Negotiations between Britain and the European Commission, the EU executive, have continued this week.
French officials accuse Britain of failing to honor its word since Brexit, citing fishing and a demand to renegotiate a protocol that aims to maintain the integrity of the EU single market.
Additional customs checks on goods traveling between Britain and the continent via the Channel Tunnel and ferries could seriously disrupt trade flows just as businesses stock up for the year-end festive period.