Foreign secretary Liz Truss has summoned the French Ambassador Catherine Colonna to meet with Britain’s Europe Minister Wendy Morton this afternoon, amid an ongoing fishing licenses row.

This latest flashpoint was triggered overnight on Wednesday, when France detained a British trawler and verbally warned another off the coast of Le Havre, and the French government subsequently threatened to hike tariffs on energy, customs, and limit port access.

In a statement yesterday evening, Brexit minister Lord Frost accused France of violating the U.K.-EU Trade and Cooperation Agreement (TCA) and thus international law warning: “We regret the confrontational language that has been consistently used by the French government on this issue, which makes this situation no easier to resolve.”

The incident could provide an awkward backdrop for this afternoon’s G20 talks in Rome, not to mention the ongoing EU talks over the Northern Ireland Protocol, and the landmark COP 26 UN climate summit set to kick off in Glasgow on Sunday.

Environment secretary George Eustice told MPs yesterday morning that the UK will “stand squarely behind Jersey” and explained that the detained trawler was granted an EU fishing permit, and that it was “unclear” why it had been removed from the list of permitted vessels.

Labour has also hit out at France’s decision, with shadow environment secretary Luke Pollard calling its threats “completely wrong and unacceptable” earlier today.

Downing Street has already said it will retaliate if France decides to block UK boats from its ports amid an ongoing row over post-Brexit fishing permits in the Channel.

A government spokesperson has said: “France’s threats are disappointing and disproportionate, and not what we would expect from a close ally and partner,” and said the proposed retaliatory measures “do not appear to be compatible” with the UK’s EU withdrawal agreement “and wider international law, and, if carried through, will be met with an appropriate and calibrated response.”

The French Maritime Ministry wrote in a tweet: “This Wednesday, two English ships were fined during classic checks off Le Havre.

“The first did not comply spontaneously: verbalisation.

“The second did not have a licence to fish in our waters: diverted to the quay and handed over to the judicial authority.”

France and Britain have been embroiled in a post Brexit dispute over fishing licenses for some time.

France has complained that its fishermen have only been granted with half the licences to fish in UK waters that they are entitled to under the Brexit agreement.

In September the UK and the Jersey refused dozens of French fishing licences.

The British government said it has granted licenses to fishing vessels with an evidenced history of operating in its waters prior to the UK’s exit from the EU.