Claudio Durigon, a member of the right-wing League, said earlier this month his party was committed to restoring the original name of the park in Latina, a city of around 120,000 residents in central Italy, to Arnaldo Mussolini.

The park was renamed in 2017 to commemorate Giovanni Falcone and Paolo Borsellino, two top anti-mafia magistrates who were murdered by the Sicilian mafia in 1992.

Latina was founded in 1932 during fascist rule and is associated with Mussolini.

"That is our history that someone wanted to cancel by changing the name of that park. It must return to being the Mussolini park," Durigon told supporters at a rally, speaking alongside League leader Matteo Salvini.

His comments sparked a political backlash, with centre-left parties within the broad unity government, which includes the League, saying they would introduce a parliamentary no-confidence motion in the undersecretary unless he quit.

With the controversy showing no sign of abating, Durigon resigned on Thursday night, acknowledging he had made a mistake and apologising to the families of mafia victims.

"I am not, and never have been, a fascist," he said in a statement.

Salvini had initially tried to defend Durigon, but came under pressure from stalwarts within his own group who were unhappy to see one of their own politicians apparently praising Mussolini's heritage.

The League is vying with the far-right Brothers of Italy for top spot in the opinion polls. Salvini thanked Durigon for stepping aside and made clear he would remain within the League.

Australian Associated Press