The leaders of Italy's main right-wing parties were due to meet Wednesday to formulate a joint battle plan for September elections, with polls pointing to victory but divisions already showing.

Giorgia Meloni's Brothers of Italy, which has neo-fascist roots, is currently topping opinion surveys at between 23 and 25 percent.

But she needs the support of allies Forza Italia, the centre-right party led by former premier Silvio Berlusconi, and Matteo Salvini's anti-immigration League to form a government.

The main topic of discussions between the trio Wednesday will be who would become prime minister to replace Mario Draghi, who resigned last week after his governing coalition collapsed.

Meloni, whose party has a Christian nationalist, anti-immigration and eurosceptic programme, said this week that without agreeing a premier in advance, "the alliance to govern together is useless".

But Salvini's League wants the party with the largest number of votes to make the choice, hoping that its own numbers will improve.

The League, which was in power as part of a populist coalition for a year after 2018 elections, is currently polling at around 12 to 14 percent, according to three surveys published Wednesday by the Corriere della Sera daily.

Media reports meanwhile suggest Berlusconi, whose Forza Italia is polling between seven and 10 percent, is concerned that naming Meloni as premier now would alienate voters alarmed by her extreme views.

Forza Italia has also suffered a wave of defections since it pulled out of Draghi's government last week, with nine lawmakers including three ministers quitting.

The League and the populist Five Star Movement also withdrew their support for Draghi's coalition, which was due to last another year, until scheduled elections in 2023.

Brothers of Italy was the only main party not to join Draghi's government when he was parachuted in to lead the eurozone's third largest economy in February 2021.

On the other side of the political spectrum, the centre-left Democratic Party is polling close to Brothers of Italy, but would struggle to win power in the absence of an alliance with other progressive parties.

The uncertainty comes as Italy implements far-reaching reforms in return for billions of euros in EU post-pandemic recovery funds, against a backdrop of soaring inflation and worries about energy supply due to the Ukraine war.

S&P Global Ratings agency revised Italy's outlook from positive to stable late Tuesday due to the risks to reforms.