Italy's two most important regions hold elections this weekend that will provide Prime Minister Giorgia Meloni and her right-wing allies with their first ballot-box test since winning power last year.

Lazio, which is centred on the national capital Rome, and Lombardy, home to the financial capital Milan, account for just over a quarter of the national population and generate a third of the Italy's total gross domestic product (GDP).

"It is fundamental that we prevail in the two regions that are at the political and economic heart of the country," said Silvio Berlusconi, a former prime minister whose Forza Italia party is part of Meloni's ruling coalition.

Polls say the right will easily keep hold of Lombardy at the Feb. 12-13 vote, despite much criticism of its handling of the COVID pandemic, which hit the region harder than almost anywhere else in Europe, raising questions about the local health system.

The right also looks poised to seize control of Lazio from the centre-left, which is still reeling from defeat in last September's national election and, as in the north, has failed to present a united front against the conservative bloc.

Internal divisions have repeatedly hobbled the left in recent years and defeat in Lazio would mean the right has control of 15 of Italy's 20 regions, underscoring its growing hegemony across the country.

TROUBLE AHEAD?

Although victory seems assured, the vote might yet destabilise the ruling coalition if Meloni's Brothers of Italy party continues to cannibalise its partners.

Brothers of Italy took 26% of the vote in the 2022 general election against just 4.5% four years earlier, winning over many disaffected League and Forza Italia voters, who were attracted by Meloni's brand of uncompromising, nationalist politics.

Opinion polls say support for Brothers of Italy has since risen to around 30%, mainly at the expense of its allies, with Meloni enjoying a prolonged honeymoon as she projects a more moderate image than the one she promoted while in opposition.

While Meloni has always thrived in her home region of Lazio, her party unexpectedly surged in the north at the 2022 election, taking twice as many votes as the League in its traditional Lombardy heartland.

If backing for the League should fall again, the future of party leader Matteo Salvini will likely come under pressure and raise doubts about his ability to push into law the party's contested flagship policy giving the regions greater autonomy.

"We can't be held hostage by Brothers of Italy," said Angelo Ciocca, a European parliamentarian with the League.

"We need a strong League that does not let the autonomy bill end up in the Roman swamps," he told Reuters.

Polls are open on both Sunday and Monday, with voting due to end at 1400 GMT on Monday. (Additional reporting by Angelo Amante Editing by Keith Weir)