Poland's governing nationalists came out on top in regional elections, but were losing to opposition centrists in mayoral races in large cities including the capital Warsaw, exit polls showed.

The local elections also took place as the PiS has put Poland on a collision course with the European Union by introducing a string of controversial judicial reforms that the bloc has warned pose a threat to judicial independence, the rule of law and ultimately to democracy.

Exit polls by the IPSOS pollsters showed the PiS winning 32.3 percent of the vote in elections to regional councils across Poland, beating a centrist-liberal coalition headed by the opposition Civic Platform (PO) with 24.7 percent.

Powerful PiS leader Jaroslaw Kaczynski hailed his party's victory as a "good sign" for next year's parliamentary elections, despite the exit poll result suggesting that the PiS is unlikely to be able to govern alone in regional councils.

The PiS currently controls only one of Poland's 16 regional councils.

Exit polls also showed the Polish Peasants' Party (PSL), traditionally strong in rural areas, winning 16.6 percent of the vote, a result likely to turn it into a kingmaker in coalition-building.

The party has previously teamed up with the PO liberals to govern at the national level.

But the PiS nationalists have failed to top in mayoral races in any major city PO liberal Rafal Trzaskowski, a 46-year-old former minister and member of the European Parliament, appeared to have won in Warsaw in the first round of voting with the IPSOS exit poll showing him on 54.1 percent against 30.9 percent for PiS candidate Patryk Jaki.

PO candidates also dominated in the first round vote in Lodz, Poznan, Lublin and Wroclaw.

Mayoral races in Gdansk and Krakow will likely be decided in a second round of voting on November 4.

Full official election results will be made public on Tuesday evening at the earliest.

(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)