WARSAW, Poland (AP) — Polish voters are casting ballots in local elections that are the first nationwide test of support for the conservative ruling party, whose policies have produced street protests and repeated clashes with European Union leaders.

The election Sunday is for offices from city mayors to village councilors, and the ruling nationalistic Law and Justice party is hoping to strengthen its firm grip on power.

The vote will also measure the strength of the opposition, which is centered on the pro-EU Civic Platform party that governed Poland for eight years before Law and Justice came to power in 2015.

The focus is on Poland's largest cities, which are traditionally pro-EU, and where the opposition is in control of local governments.