Two British naval gunboats have arrived off the coast of Jersey as about 80 French boats also gathered at the port in St Helier in protest over post-Brexit rules on fishing rights.
HMS Severn and HMS Tamar held back while observing the French flotilla amassing at about 6am south of the Channel Island capital before heading into the port just before 7am.
Downing Street said the gunboats had been sent to “monitor the situation” but some criticised the decision as heavy-handed gunboat diplomacy designed to boost the Conservatives credentials on the day of local elections across Britain.
French fishers are protesting over new licences issued on Friday that restrict the number of days they can operate in shared waters for the first time.
Up to now they have been allowed fish under the 200-year-old Bay of Glanville treaty, which Jersey Fishermen’s Association president, Don Thompson, says allowed them authorise their own fishing licences leading to declining fish stocks.
But there was also support among some Jersey fishers for the protest.
Chris Le Masurier, the owner of the Jersey Oyster Company, described conditions placed upon the new post-Brexit fishing licences issued to Breton and Norman fishers as “insulting and discriminatory”.
The two navy ships were sent overnight amid a war of words over the new regime, which intensified when a French marine minister hinted they could cut off the electricity supplies.
The French government says the licensing system for fishers that Jersey introduced on Friday is unfair and unacceptable.
Fishers were intent on ensuring the protest was peaceful, and shortly after 7am cleared the exit from the harbour to allow a freight vessel out.
Boris Johnson dispatched two Royal Navy patrol boats to protect Jersey from a feared blockade on Wednesday night.
The move followed talks between the prime minister and the chief minister of the British crown dependency, John Le Fondré, who had warned Downing Street of imminent movements by French fishing boats to cut off the island’s main port.
Jersey’s government had already been reeling from comments on Tuesday from France’s minister for maritime affairs, Annick Girardin, who had warned that the island’s electricity supply could be turned off in retaliation over a lack of access for the French fishing fleet to its waters.
The mobilisation echoes the cod wars of the 1970s, when there were violent clashes on the high seas between British vessels and Icelandic fishers.
A Downing Street spokesperson said Johnson had “underlined his unwavering support for Jersey” in the crisis, describing any threat to blockade Jersey’s main entry point for vital supplies as “unjustified”.
“As a precautionary measure the UK will be sending two offshore patrol vessels to monitor the situation … They agreed the UK and Jersey governments would continue to work closely on this issue.”
Craig Murray, a former British ambassador, said he could “not believe how stupid, on every level, it is to send gunboats”.
Murray, the former head of the marine section at the Foreign and Commonwealth Office, tweeted that he had personally negotiated the UK’s fisheries agreement between France and the Channel Islands in 1991. The talks were “heated”, he said.