French officials lashed out at Britain on Friday over a letter from Prime Minister Boris Johnson advising France to take back migrants who reach British shores, escalating a diplomatic spat just days after 27 people died trying to cross the English Channel.

The French denounced Johnson’s statement in blunt terms, calling it unacceptable, and disinvited Britain’s home secretary, Priti Patel, from a crucial meeting on the migrant crisis on Sunday.

The dispute, in the immediate aftermath of one of the deadliest disasters ever in the English Channel, underscored the diplomatic hurdles the two countries face in addressing the problem, as lingering tension over Brexit and disagreements on issues including trade and fishing rights continue to roil their relationship.

In a letter sent to President Emmanuel Macron of France on Thursday night, Boris wrote that France and Britain should “put in place a bilateral readmissions agreement to allow all illegal migrants who cross the Channel to be returned”, suggesting that if France took back migrants it would be a major step towards fixing the problem.

The letter prompted a fierce reaction from Gabriel Attal, a French government spokesman, who said the letter was “both poor in content and completely inappropriate in its form”.

“Enough with the doublespeak, enough with the constant externalisation of problems,” Attal, visibly irritated, told BFMTV on Friday morning. “It makes you wonder if Boris Johnson doesn’t regret having left Europe, because every time he has a problem, he thinks that Europe should handle it.”

Gérald Darmanin, France’s interior minister, quickly announced that Patel was no longer invited to an emergency meeting that France will hold in Calais on Sunday with ministers in charge of immigration from neighbouring countries like Belgium and Germany.

Macron said on Friday that the crisis required “serious” cooperation — but that Boris’s letter was not a serious effort.

“You don’t communicate from one leader to another on these issues by tweets and by letters that you make public, we aren’t whistleblowers, come on,” Macron said at a news conference in Rome, where he was on an official visit.

On Wednesday, about 30 migrants crammed onto a flimsy inflatable vessel were shipwrecked in the English Channel’s frigid waters, and most of them — men, women and children — drowned. French prosecutors have opened an investigation to determine the exact circumstances of the disaster.

The number of migrants setting off into the sea has soared in recent months because France has cracked down on other routes to England, especially by ferry or by truck and train through the tunnel under the Channel. So far this year, there have been 47,000 attempts to cross the Channel, and 7,800 migrants had been saved from shipwrecks, according to French officials.

On Twitter, where he also published the full letter to Macron, Boris wrote that “an agreement with France to take back migrants who cross the Channel through this dangerous route would have an immediate and significant impact”.

New York Times News Service