The French government could cut off the electricity supply to Jersey in an escalating row over post-Brexit fishing rights, a French minister has suggested. Responding to questions in the national assembly, Annick Girardin, the minister for maritime affairs, said she was “revolted” by the UK government’s behaviour over its waters and France was ready to retaliate. The British crown dependency of Jersey, the largest of the Channel Islands, relies on “the transmission of electricity by underwater cable”, Girardin said as she was questioned by assembly members, raising the supply as a point of leverage. “I would regret it if we were to get there,” the minister said, but “we will do so if we have to.” The comments mark a major escalation in a row over claims by French fishers that they are being denied access to UK waters. David Frost, the former chief Brexit negotiator who is now the minister responsible for relations with the EU, held scheduled talks with the French minister of European affairs, Clément Beaune, on Tuesday afternoon. It is claimed that the UK government is using red tape to limit the operations of French fishing vessels, in contravention of the trade and cooperation agreement struck with the EU on Christmas Eve. The UK government denies the claim, saying Jersey alone is responsible for the management of its waters. On Friday, 41 ships equipped with Vessel Monitoring System (VMS) technology, which allows ships to be located, were authorised to fish in waters off Jersey, which is a self-governing dependency. Girardin told the French parliament that the list of approved ships had come with new rules “which were not arranged or discussed [with France], and which we were not notified about”. One assembly member, Bertrand Sorre, said a fisher from Granville, who fishes for scallops and whelks “on average 40 days a year” in Jersey waters, had been told he would only have access for 11 days. “The anger is roaring and the desire to do battle is palpable,” Sorre said. Girardin responded that the French government would act. “It is completely unacceptable,” she said. “If we accept it in Jersey, it is dangerous for our access everywhere.” France has described the UK’s provisions, which it says dictate where vessels can and cannot go and specify how many days vessels may spend in the waters and what equipment they may use, as “null and void”. The UK government has been told it needs to open discussions with the European Commission on the details. Dimitri Rogoff, the president of the Normandy regional fisheries committee, told Agence France-Presse there “will need to be a response to what the Jersey authorities have done in relation to fishing authorisations. We hope that the state will take retaliatory measures.” A Defra spokesperson said: “We are clear that Jersey is responsible for its own territorial waters. The UK government is constitutionally responsible for the international relations of the crown dependencies. As such, we have been working closely with the EU and the government of Jersey on fisheries access provisions following the end of the transition period for licensing.” Last week Beaune threatened to stand in the way of access for UK-based financial companies to the EU market if issues over fishing rights persisted. “We are asking for the whole agreement, nothing but the agreement, and as long as it is not implemented we will take retaliatory measures in other sectors if necessary,” Beaune said. “The UK is expecting a number of authorisations from us on financial services. We will not give any until we have guarantees that on fisheries and other issues, the UK respects its commitments. It’s give and take. Each side should respect its commitments, otherwise we will be as brutal and difficult as necessary.” French fishers recently blockaded the port of Boulogne-sur-Mer, claiming that only 22 of the 120 boats that usually worked from the Hauts-de-France had been given access to the zone six to 12 miles from the UK coast. The UK government has denied the claim. It said the UK Single Issuing Authority had issued licences to fish in the six to 12 nautical mile zone to all 87 French vessels that had applied for them and met the qualifying criteria. About 40 additional applications required further information and checks, the government added.