Italy¡¯s center-left opposition is testing out a big-tent alliance on the guess that it¡¯s the best way to unseat Italian Prime Minister Giorgia Meloni at the next general election.

The rest is still being worked out.

The alliance pulls together parties with disparate political beliefs ¡ª the center-left Democrats, the populist Five Star Movement, the left-wing Greens and Left Alliance and several smaller groups. The goal is to rally behind single, strategically chosen candidates and consolidate the anti-Meloni vote.

The plan will get a crucial test on Sunday and Monday during gubernatorial elections in Campania and Veneto. The outcomes there will offer early bellwethers of the electorate¡¯s mood.

Polling shows an opposition alliance could notch a tie or even a majority in the Senate at the next general election, due by 2027. The prospect has even prompted Meloni to explore election law changes that would damage the opposition.

But the coalition has a mixed track record thus far in key regional elections and lacks a clear public face or political platform.

¡°There¡¯s an evident problem in terms of who the political leader is,¡± said Vera Capperucci, a political history professor at Luiss University in Rome. ¡°There¡¯s no definition of how wide it would be.¡±

There will be two main battlefields for the opposition to test its assumptions this weekend.

In Campania, the alliance¡¯s candidate, Roberto Fico, is seen as the front-runner for the southern region that includes Naples. A former press officer, Fico is a national political figure who first entered parliament after winning a Five Star Movement primary with just 228 votes.

Edmondo Cirielli, part of Meloni¡¯s Brothers of Italy party and currently an undersecretary at the foreign ministry, is the center-right¡¯s candidate.

In Veneto, the center right is favored. The rich northeastern region has traditionally leaned right and was one of the early breeding grounds for the League, the right-wing party in Meloni¡¯s governing coalition.

Veneto could also offer indications of where the power lies within Meloni¡¯s coalition.

If the League loses its regional primacy to Meloni¡¯s Brothers of Italy, that would give the prime minister extra clout as she weighs the makeup of her coalition in the next election. The League¡¯s leader, Matteo Salvini, has already suffered a series of setbacks recently, including on his flagship €13.5 billion ($15.5 billion) bridge to Sicily.

Voters in Apulia, where the center left is seen as favored, are also headed to the polls in the coming days.

In prior regional elections, the opposition coalition has scored a win in Tuscany, a bastion of the left, but flunked other key contests in Marche and Calabria.

Meloni has proved durable as prime minister, despite occasional clashes within her coalition...