Tensions sizzle after a sausage-themed dispute between the British and French leaders over post-Brexit trading arrangements in Northern Ireland and over London's refusal to implement checks on goods heading into Northern Ireland.
Britain has accused European Union leaders of holding the "offensive" view that Northern Ireland is not fully part of the United Kingdom, as Brexit cast a shadow over the Group of Seven summit.
British media reported on Sunday that Prime Minister Boris Johnson asked French President Emmanuel Macron when they met Saturday in the English seaside resort of Carbis Bay how he would feel if sausages from Toulouse could not be moved to Paris.
They said Macron replied the comparison did not work because Paris and Tolouse were part of the same country.
The French presidency did not deny Macron had made the comments. It said he was explaining “that Toulouse and Paris were on a geographical unity of territory, Northern Ireland is on an island. The president wanted to stress that the situation was quite different and that it’s not appropriate to hold that kind of comparison.”
Britain and the EU are in a spat over post-Brexit trade arrangements that could see British sausages banned from entering Northern Ireland, the only part of the UK that borders the 27-nation bloc. The dispute is raising political tensions in Northern Ireland, where some people identify as British and some as Irish.
British Foreign Secretary Dominic Raab went further in demanding the EU show more "respect" for the UK's territorial integrity and avoid "ignorant comments".
"We have seen senior EU figures talk about Northern Ireland as if it were somehow a different country to the UK," he said, calling it "offensive" and damaging to the restive province's communities.
"Can you imagine if we talked about Catalonia, the Flemish part of Belgium, northern Italy, Corsican France, as different countries?"
French officials described the meeting as "tense", although Johnson's spokesman insisted he and Macron still had a "constructive" relationship.
The leader of Northern Ireland's pro-British Democratic Unionist Party, Edwin Poots, was outraged and demanded that France "recognises Northern Ireland's constitutional status".
"Key leaders in the European Union clearly do not even understand the basics let alone the finer details," he said in a statement.
"It is time for the (UK) government to stop talking about fixes to the protocol and get on with taking the necessary steps to remove it."
The Northern Ireland Protocol, signed separately from the Brexit trade deal agreed in December, is supposed to see checks on goods heading into the province from mainland Britain.
Unionists say it has driven a wedge between Northern Ireland and the rest of the UK, and makes reunification of Ireland more likely.
The arrangement effectively keeps Northern Ireland in the European customs union and single market that the UK left in January, to stop unchecked goods going to the bloc via neighbouring EU state Ireland.
Northern Ireland suffered three decades of violence over British rule, which ended with the signing of a landmark peace deal in 1998.
But the protocol has inflamed lingering tensions, and has been blamed for recent violence.