French President Emmanuel Macron said on Monday that retaliatory measures threatened against Britain over a row about post-Brexit fishing rights would not be implemented at midnight, with fresh talks planned this week.

Discussions will "continue tomorrow" between France, the UK and the European Commission, Macron said on the sidelines of the COP26 summit in Glasgow.

He ruled out the application of French reprisals for the time being because "it's not while we're negotiating that we're going to impose sanctions".

Britain welcomed Macron's announcement.

Brexit minister David Frost said he had accepted an offer from French Europe Minister Clement Beaune to meet. "I look forward to our talks in Paris on Thursday," Frost tweeted.

The British fishing trawler Cornelis-Gert Jan was detained in the French port of Le Havre, allegedly for fishing without the required licence
The British fishing trawler Cornelis-Gert Jan was detained in the French port of Le Havre, allegedly for fishing without the required licence AFP / Sameer Al-DOUMY

Announcing the invitation to Frost to come for "in-depth discussions", Beaune tweeted that Britain had sent "the first signals... to accelerate exchanges".

France had vowed to subject British imports to tighter controls starting from Tuesday, in a bitter row over fishing rights that has grown since Brexit took full effect at the start of the year.

It had said it would prevent British fishermen offloading their catches in French ports, after Britain and the Channel Islands of Jersey and Guernsey declined to issue dozens of French boats with licences to fish in their waters after Brexit.

In a statement, a UK government spokesperson added: "We welcome the French government's announcement that they will not go ahead with implementing their proposed measures as planned tomorrow.

"As we have said consistently, we are ready to continue intensive discussions on fisheries, including considering any new evidence to support the remaining license applications," the spokesperson said.

Map of Britain and neighbouring countries' Exclusive Economics Zones, with fishing waters around Britain.
Map of Britain and neighbouring countries' Exclusive Economics Zones, with fishing waters around Britain. AFP / Kenan AUGEARD

"We welcome France's acknowledgement that in-depth discussions are needed to resolve the range of difficulties in the UK/EU relationship."

The feud has already seen a British trawler detained in a French port and France's ambassador in London summoned to the Foreign Office for the type of rebuke usually reserved for hostile states.

Macron said he had "confidence in British Prime Minister Boris Johnson to take seriously" the French proposals and for the discussions to lead to a "result".

"For 10 months the results have been too slow, if this new method allows us to have a result, I hope we will give it a chance," he said.

Britain's Prime Minister Boris Johnson (l) and French President Emmanuel Macron ahead of the COP26 UN Climate Change Conference in Glasgow on Monday
Britain's Prime Minister Boris Johnson (l) and French President Emmanuel Macron ahead of the COP26 UN Climate Change Conference in Glasgow on Monday POOL / Christopher Furlong

The latest post-Brexit row between France and Britain comes as Macron continues to fume over London's involvement in a defence pact with the United States and Australia that cost France a multi-billion-euro submarine deal.

There was no outward sign of tension as Johnson welcomed Macron to the COP26 climate summit, with the two leaders smiling and chatting for several minutes

But in Brussels, officials scrambled behind the scenes to head off a showdown by hosting a meeting of representatives from France, Britain and the Channel islands to try to defuse the row.

With just hours to go before the deadline, both sides were sticking to uncompromising positions, with Britain's Foreign Secretary Liz Truss threatening to sue France and embroil the rest of the EU.

"If somebody behaves unfairly in a trade deal you're entitled to take action against them and seek some compensatory measures. And that is what we will do if the French don't back down," told Sky News.

Britain has also threatened to step up inspections of EU fishing vessels.

The head of the regional fisheries committee of France's northern Hauts-de-France region, Olivier Lepretre said on Monday he feared that fishermen would be turned back from British waters "over the slightest issue."

If provoked, he said, French fishermen, who have staged protests in Channel ports in recent months, would "show some muscle" and carry out further action.

France says that dozens of French fishermen are waiting for licences to ply waters between six and 12 miles from British shores, and in particular around Jersey.

After talks with Johnson on the sidelines of a G20 summit in Rome on Sunday, Macron said the two leaders had agreed to work on "practical and operational measures" but insisted: "The ball is in Britain's court."

Johnson however denied that Britain's position had changed, insisting France must back down first.

A day earlier he had complained to EU chief Ursula von der Leyen over the "completely unjustified" French threats and raised the possibility of invoking a Brexit dispute tool for the first time, drawing the EU into the row.