France and Britain held a second day of talks on Tuesday to try resolve a months-long row over fishing licences that has threatened to escalate into a full-blown trade war.

But British Prime Minister Boris Johnson made it clear that London's position had not changed.

On Monday evening, with just hours to go to a deadline for Britain to grant dozens of French fishermen new permits or face retaliatory measures from Paris, French President Emmanuel Macron bought the negotiations extra time.

France had threatened to ban British boats from unloading their catches at French ports
France had threatened to ban British boats from unloading their catches at French ports AFP / Sameer Al-DOUMY

While talks were underway, he declared, France would not implement threats to ban British boats from unloading their catches at French ports and to subject all British imports to inspections.

"It's not while we're negotiating that we're going to impose sanctions," Macron said on the sidelines of the COP26 summit in Glasgow, remarks welcomed by the British government.

Macron's office later confirmed that sanctions were off the table "until Thursday at the earliest", when Britain's Brexit minister David Frost is due in Paris for talks with France's Europe minister Clement Beaune.

"Talks continued today," said a spokesman for the European Commission, which is brokering the talks.

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

"It is positive and reassuring to see contacts aiming at a solution. Technical meetings to resume on Wednesday."

A source in the French presidency stressed to AFP Tuesday that the threat of reprisals remained. Paris was awaiting a response from London to its latest proposals by Wednesday, the source added.

British PM says UK stands firm on French fishing row
British PM says UK stands firm on French fishing row AFPTV / Kate GILLAM

But on Tuesday evening, asked whether London had shifted stance in the face of French threats of retaliatory measures, Johnson told reporters: "The answer is no."

As Glasgow hosted the crucial COP26 conference on measures to tackle climate change, Johnson made it clear that the fishing row -- and Macron's early departure from the summit -- were, in comparison, "vanishingly unimportant".

The feud centres on the rights of small-scale fishermen in northern France to continue operating in the waters surrounding the UK and Channel Islands in the post-Brexit era.

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

Under a deal agreed by Britain and the EU late last year, European fishing vessels can continue to ply UK waters if they can prove they operated there in the past.

But dozens of French boats have had their applications to operate in the UK's fish-rich waters rejected.

In France, where campaigning has begun for next year's presidential election, politicians from both right and left urged Macron to take a stern line.

"I'm all for giving it an extra 48 hours but we'll have to be very tough indeed with the British at that point," conservative presidential hopeful Xavier Bertrand told France 2 television.

His sentiments were echoed by a leading Socialist, Patrick Kanner.

"France is right to flex its muscles but when you do so sometimes you have to go all the way," the senator told France Info radio.

Macron's decision to defer retaliatory measures marks a de-escalation in the tensions which had been building between France and Britain for weeks.

Paris is still angry over London's involvement in a new defence pact with the US and Australia that left France out in the cold.

The two neighbours have also sparred over the spike in the number of migrants slipping across the Channel to Britain.

Britain and Jersey claim French fishermen have failed to provide sufficient documentation to support their licence applications and threatened to sue France if it disrupts trade flows.

"If somebody behaves unfairly in a trade deal you're entitled to take action against them and seek some compensatory measures," Britain's Foreign Secretary Liz Truss said Sunday.

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.