CALAIS, France (AFP) – On Sunday, France will host a conference of European ministers to explore measures to prevent migrants from crossing the Channel in dinghies, but Britain will be absent due to a disagreement last week.

Ministers from France, Germany, the Netherlands, and Belgium will meet on Sunday afternoon in the northern French port of Calais to discuss ways to combat people-smuggling gangs that provide boats to migrants attempting to cross the narrow channel.

The meeting was convened in response to the terrible deaths of 27 individuals last Wednesday while attempting to cross from France to England in a dinghy that began losing oxygen out at sea in severe winter weather.

The meeting’s goal is to “improve operational collaboration in the fight against people smuggling because these are multinational networks operating in different European countries,” according to an assistant to French Interior Minister Gerald Darmanin.

The major emphasis had been intended to be meetings between Darmanin and his British colleague Priti Patel, after both nations committed to collaborate more closely in the aftermath of the horrific drownings.

Working more closely would need Paris and London overcoming years of animosity produced by Britain’s exit from the European Union, as well as sometimes icy ties between their administrations.

Within 48 hours after the tragedy, French President Emmanuel Macron accused British Prime Minister Boris Johnson of being “not serious,” in an extraordinarily personal attack that strained relations even further.

France was irritated by Johnson’s initial reaction, which was perceived as blaming France, and then by his decision to send a letter to Macron, which he published in full on his Twitter account before the French leader had read it.

Patel’s invitation to the discussions on Sunday was quickly rescinded, with a Darmanin official calling Johnson’s public letter “inappropriate.”