France’s pro-EU government and Italy’s populist leaders sparred anew Friday, as business giants from both countries appealed for calm amid the neighbors’ biggest diplomatic spat since World War II, AP reported.

France said the stunning recall of its ambassador to Italy was a temporary move — but an important signal to its historical ally not to meddle in internal French affairs.

French officials said Friday that this week’s recall of French Ambassador Christian Masset was prompted by months of “unfounded attacks” from Italian government members Luigi Di Maio and Matteo Salvini, who have criticized French President Emmanuel Macron’s economic and migration policies.

But the main trigger for the crisis appeared to be Di Maio’s meeting in a Paris suburb this week with members of the yellow vests, a French anti-government movement seeking seats in the European Parliament.

French government spokesman Benjamin Griveaux said the visit violated “the most elementary diplomacy” because it was unannounced. Referring to Italy’s populist leaders, he criticized a “nationalist leprosy” eating away at Europe’s unity and said EU members should “behave better toward partners.”