An Italian court gave the green light Tuesday to a fresh defamation case brought by Prime Minister Giorgia Meloni, this time against a historian who called the far-right leader a "neo-Nazi at heart".

Left-wing classicist Luciano Canfora, 81, made the comments during a school debate in Bari, southern Italy, in April 2022 -- six months before the Brothers of Italy leader took office following a historic election win.

The trial is set to open on October 7, with Meloni seeking 20,000 euros ($21,260) in damages.

Meloni last year successfully sued journalist Roberto Saviano for criticizing her stance against migrants in December 2020, with an Italian court handing him a suspended fine of 1,000 euros.

She has also brought a suit against the frontman of British rock band Placebo, after he called her "racist" and "fascist" during a performance in Italy in July 2023. That trial has yet to get underway.

Meloni had posted a video of Canfora speaking on Facebook, alongside a comment condemning his "unacceptable words" which she said amounted to "vulgar propaganda to young students".

Speaking to AFP ahead of Tuesday's hearing in a tribunal in Bari, Canfora -- a former professor in Greek and Latin philology at the University of Bari who is well-known in Italy -- was unrepentant.

"When you say neo-Nazi, you don't think of someone who is perpetrating crimes, or murders, you think of someone who still has some ideas, some mental attitudes that hark back to the past," Canfora said.

He noted that in her 2021 autobiography "I am Giorgia", Meloni wrote about having "taken up the baton" of Italy's post-war far-right leaders, including Giorgio Almirante.

Almirante was one of the founders of the now-defunct Italian Social Movement (MSI), a party formed by supporters of Fascist dictator Benito Mussolini after World War II.

He was also an official of the Italian Social Republic (RSI), a wartime Nazi-controlled puppet state.

Meloni's Brothers of Italy is a political descendant of the MSI, although she told parliament when she took office that she had "never felt sympathy or closeness to undemocratic regimes... including Fascism".

Canfora has been supported by many Italian and foreign intellectuals in fighting his case, with French left-wing newspaper Liberation organizing a petition to support him.

On Tuesday he told AFP he would see the trial as "encouragement to delve even further into the study of post-fascist Italy".