Boris Johnson has refused to rule out triggering the dispute mechanism clause in the Brexit trade agreement after suggesting France had breached the terms of the deal with its fishing threats.
The Prime Minister says "we'll do whatever is necessary to protect British interests."
Prime Minister Boris Johnson (center) and French President Emmanuel Macron do a fist bump as they gather with other world leaders gather for a group picture at the La Nuvola conference center during the G20 summit.
Kirsty Wigglesworth
However he attempted to divert attention away from the row, saying, on, 'I think that what we need to focus on, what the French need to focus on, and what we all need to focus on, are the much much bigger things that we have before us - particularly tackling climate change.'
This comes after French president Emmanuel Macron, in an interview with the Financial Times, accused the UK of not keeping its Brexit pledges on fishing as he said London lacked “credibility”.
The country’s prime minister Jean Castex, meanwhile, has written to European Commission president Ursula von der Leyen to encourage Brussels to back Paris’ position against London.
France is threatening to block British boats from its ports and tighten checks on vessels if an issue over a lack of licences for small French vessels to fish in British waters is not resolved by Tuesday.
Mr Castex urged the EU to use the “levers at its disposal” to press home the need for “compliance” with the Brexit agreement on fishing and to show that “leaving the Union is more damaging than remaining in it”.
But Jean-Marc Puissesseau, president and chairman of the ports of Calais and Boulogne-sur-Mer, described the argument as “ridiculous” as he urged both sides to dial down talk of threats and retaliation.
The captain of the Cornelis Gert Jan vessel, understood to be an Irish national, was detained in Le Havre during the diplomatic storm and has been told to face a court hearing in August next year.
French authorities allege the Cornelis Gert Jan did not have a licence, a claim the boat’s owner, Macduff Shellfish, denies. The EU said UK authorities withdrew the licence on March 1.
Foreign Secretary Liz Truss took the rare step of ordering an allied nation’s envoy to be summoned as she called Catherine Colonna, French ambassador to the UK, to the Foreign Office on Friday afternoon to challenge her over France’s stance.
The meeting came after ministers promised retaliation if France did not back down over its proposals if next week’s deadline for increased licences is not met.
At the centre of the dispute are the licences for small boats, which are issued only if the vessels can demonstrate a history of fishing in British waters.