Annick Girardin, French minister for maritime affairs, warned France could use the islands electricity supply as leverage in a row over fishing rights. On Thursday two Royal Navy patrol ships watched on as 60 French fishing boats protests off the coast of St Helier, the island’s de facto capital.
During the protest one French vessel was filmed ramming into a British boat, though there was no sign of serious damage.
Writing in the Daily Mail Lord Hannan, a prominent Brexit advocate and former Tory MEP, condemned the French behaviour.
He said: “A stable democracy doesn’t threaten to cut off its neighbour’s energy supplies.
“That is the sort of behaviour we associate with rogue states.
“Putin’s Russia, for example, sometimes resorts to ‘gas diplomacy’ to browbeat Ukraine and other nearby states.
“An energy blockade is calculatedly bellicose — if not exactly an act of war, then certainly a declaration of hostile intent.
“Incredibly, such a threat is now being made by the French government against Jersey, a British Crown dependency 14 miles from the Normandy coast, in a row over fishing licences.”
French fishermen claim their access to UK waters has been reduced since Britain left the EU’s Common Agricultural Policy at the end of December.
READ MORE: France’s failed legal bid to challenge Jersey and Guernsey’s UK links
Lord Hannan argued increasingly authoritarian behaviour from Mr Macron is playing a role in the dispute.
He wrote: “France is supposed to be a Nato ally.
“Yet here it is threatening the sort of sanctions that might be more aptly deployed against an enemy, such as North Korea.
“Part of the explanation might lie in Emmanuel Macron’s increasingly dictatorial behaviour.
“It is extraordinary to think that the French president was once hailed as a liberal centrist.
“His grandiose gestures — yesterday, he laid a wreath at the tomb of Napoleon, who destroyed the French republic with a putsch then plunged Europe into a series of disastrous wars — suggest autocracy rather than moderation.”
Speaking to Reuters news agency Hugo Lehuby, a spokesman for Normandy fishermen, warned there could be further French protests.
He said: “We’re getting deeper into deadlock.
“Either this gets resolved, or retaliatory measures are taken.”
HMS Severn and HMS Tamar are to remain off Jersey “as a precautionary measure”.