A tense post-Brexit standoff between France and Britain eased Thursday, as London recalled two navy vessels sent to Jersey and protesting French fishermen returned home without blockading the island's main port.

The latest blow to cross-Channel relations was caused by angry French fishermen protesting over new fish licensing arrangements on the Channel island following Britain's departure from the European Union.

At dawn, a flotilla of around 50 trawlers had massed in front of the Saint Helier harbour on Jersey, a picturesque self-governing territory that is dependent on Britain for its defence.

French fishing boats massed Thursday at the main port at Saint Helier, on the Channel island of Jersey French fishing boats massed Thursday at the main port at Saint Helier, on the Channel island of Jersey Photo: AFP / Sameer Al-DOUMY

Fears of a blockade prompted British Prime Minister Boris Johnson to send two Royal Navy gunboats to the area, with France following suit by sending two of its own coast patrol vessels.

But after the fishing vessels withdrew in the afternoon, Johnson ordered the return of the navy vessels.

"Given the situation is resolved for now, the Royal Navy Offshore Patrol Vessels will prepare to return to port in the UK," said a statement from his office.

French fishermen have complained about new licensing requirements announced by Jersey authorities French fishermen have complained about new licensing requirements announced by Jersey authorities Photo: AFP / Sameer Al-DOUMY

"We remain on standby to provide any further assistance Jersey requests."

Jersey lies just off France's northern coast and its rich fishing waters were previously open to French boats before Brexit tore up the previous arrangements.

In the middle of the afternoon, after hours of bobbing around while letting off the occasional smoke flare, the French trawlers began withdrawing.

A flare is lit as French fishing boats protest in front of the Jersey port of Saint Helier on Thursday A flare is lit as French fishing boats protest in front of the Jersey port of Saint Helier on Thursday Photo: AFP / Sameer Al-DOUMY

"The show of force is over, now it's politics that has to pick up the baton," said Dimitri Rogoff, president of the fishing association in the French Normandy region.

The British navy vessels HMS Severn and HMS Tamar were sent to Jersey's waters to "monitor the situation", the UK government said, while a French military source said the situation was "very calm overall".

Johnson spoke to Jersey's Chief Minister John Le Fondre on Wednesday and the pair "stressed the urgent need for a de-escalation in tensions", according to a statement.

French fishing boats massed Thursday at the main port at Saint Helier, on the Channel island of Jersey French fishing boats massed Thursday at the main port at Saint Helier, on the Channel island of Jersey Photo: AFP / Sameer Al-DOUMY

In the run up to Thursday's protest, French fishermen had been loudly complaining about new licensing requirements announced by Jersey authorities.

They view the paperwork as deliberately obstructing them -- the same charge made by other French boat owners who have denounced delays in the licensing process for access to British waters.

The Channel island of Jersey The Channel island of Jersey Photo: AFP / Gal ROMA

At the end of last month, more than a hundred French fishermen briefly blocked trucks carrying British fish to processing plants in the port of Boulogne-sur-Mer.

French Maritime Minister Annick Girardin escalated tensions with Jersey on Tuesday by warning that France could cut off electricity supplies to the island, a threat condemned by London as "unacceptable".

Jersey Minister for External Relations Ian Gorst told AFP that Girardin's comments were "completely inappropriate".

"Let's not have rhetoric, let's not have threats -- let's sit down with the EU," he said. "We have to do the hard work and find ways to resolve the issues."

But France's Europe Minister Clement Beaune accused Britain of being to blame for the spat, insisting that French fishermen should have the right to continue working in these waters.

"Our wish is not to have tensions, but to have a quick and full application of the (Brexit) deal," he told AFP.

One of the French patrol boats deployed to the area was from the gendarme military police force, while the other was a coastal security vessel operated by the maritime ministry.

The escalating tensions landed on the front pages of most British newspapers.

"Boris sends gunboats into Jersey," read a Daily Mail headline, while The Daily Telegraph said Johnson had sent the navy to the island to "face the French".

On social media, some pointed out that the standoff was taking place just a day after the 200th anniversary of the death of Napoleon, whose rivalry with the British crown was legendary.

Mujtaba Rahman, an analyst from the Eurasia Group consultancy, suggested Johnson's decision to deploy the navy would give him a boost on a day when Britons were voting in local and regional elections.

"Although feelings are running high among the fishermen, some concessions over licences is likely to eventually calm matters," he wrote.

In October 2018, dozens of French scallop fishermen faced off with a handful of British rivals off Frances coast, with a few vessels ramming into each other amid stone-throwing and smoke-bombs.