France has taken the exceptional step of recalling its envoy to Rome in protest to a series of attacks from Italy’s populist leaders, which it described as “unprecedented” since World War II.

The last time France recalled its ambassador to Rome was back in 1940.

Benito Mussolini’s Italy had just declared war on France – an opportunistic “stab in the back”, said the then ambassador André François-Poncet as he hastily left the Palazzo Farnese, the elegant Renaissance palace housing the French embassy.

A professor of political science at the University of Trieste in Italy, Paolo Feltrin said this is what happened in the old days: first they recalled their ambassador, then they went to war.”

With an armed conflict between the two neighbours and allies now unthinkable, France’s decision to recall its Rome envoy on Thursday is “first and foremost a theatrical move”, said Feltrin, describing the escalating dispute between two founding members of the European Union as a “stunt” dictated by domestic concerns on either side of the Alps.

The ambassador’s repatriation caps an astonishing deterioration in relations between Rome and Paris, just 13 months after French President Emmanuel Macron and Italy’s previous government announced plans to sign a Franco-Italian friendship treaty.

The move follows a series of increasingly personal slurs levelled at Macron by Italy’s two deputy prime ministers, Luigi Di Maio and Matteo Salvini, who formed a populist coalition government last year.

The taunts reached tipping point this week when Di Maio, who heads the anti-establishment Five-Star Movement, paid a visit to French Yellow Vest anti-government protesters outside Paris.