The French government has warned it could cut electricity to Jersey amid an escalating row over post-Brexit fishing rights, APA reports citing BBC.
Maritime Minister Annick Girardin told the French parliament that new rules governing access to Channel Islands waters were unacceptable.
She said France was "ready to use... retaliatory measures" under the UK-EU post-Brexit trade deal.
"I am sorry it has come to this [but] we will do so if we have to," she said.
Jersey, the largest of the Channel Islands, receives 95% of its electricity through three underwater cables from France.
In a statement to AFP news agency, the French fisheries ministry said the UK had introduced "new technical measures" linked to licences for fishing off the Channel Islands which had not been communicated to the EU and were therefore "null and void".
Meanwhile, the UK's Department for Environment, Food and Rural Affairs said: "We are clear that Jersey is responsible for its own territorial waters."
The latest comments mark an escalation in the row over fishing rights, which has been simmering for months and marked a key sticking point in post-Brexit trade talks.