The UK has rejected French claims of a deal to try to end the “fish wars” between the two countries, leaving Paris on course to launch reprisals in just 48 hours.
France claimed Emmanuel Macron and Boris Johnson had agreed to work on “practical measures” to resolve the dispute – but No 10 insisted that was wrong and it is up to France to back down.
The prime minister’s spokesman suggested Paris had given no indication it will drop its deadline of Tuesday to snarl up cross-Channel trade with port restrictions and border checks.
As a result, the UK is standing by its threat to launch a legal battle and do “whatever is necessary to ensure UK interests”, Mr Johnson has said.
“We stand ready to respond should they proceed to breaking the Brexit agreement,” his spokesman told reporters at the G20 summit in Rome.
The UK had not agreed to take any different measures, such as relaxing the rules for issuing licences, after French boats were denied access to UK waters they say they have fished for decades.
“Our position has not changed in regard to enforcing the Brexit deal as agreed by both sides.” the spokesman said.
And he added: “It will be for the French to decide if they want to step away from the threats they have made in recent days.”
The fresh clash leaves the UK and France still locking horns as the Cop26 climate summit gets underway in Glasgow, to the despair of environmental campaigners.
London is “actively considering” triggering a dispute resolution mechanism in the post-Brexit trade deal that would send the dispute to independent arbitration – and a potential trade war if that fails.
Mr Macron, meanwhile, has appealed to the EU for support, calling the row a test of the UK’s credibility and reliability in the eyes of the world.
France has warned it will bar UK fishing boats from some ports and tighten customs checks on lorries entering the country with British goods – from Tuesday – unless more licences are released.
Clement Beaune, France’s Europe minister, tweeted that Paris “stands ready to implement proportionate and reversible measures from November 2, as we have announced repeatedly since last April”.
The 30-minute meeting also saw the two leaders continue the equally damaging stand-off over the Northern Ireland Protocol, where the UK is also threatening to invoke the dispute mechanism of Article 16.
Mr Johnson’s spokesman said he had informed the French president that the Protocol “was the most important issue currently affecting UK-EU relations”
“The prime minister stressed the need to urgently agree a solution in order to protect the Belfast [Good Friday] Agreement, including on governance,” a statement read.
