(Bloomberg) -- A candidate backed by a bloc of pro-European Polish opposition groups comfortably won a race for city mayor in the south-east region that’s been a stronghold of the ruling Law & Justice party, an exit poll showed.

If confirmed, the result in Rzeszow shows that when united, the opposition can effectively compete against the powerful ruling party, which remains well ahead in nationwide opinion polls midway through its second parliamentary term.

Konrad Fijolek won 55.8% of the vote, according to an exit poll published by broadcaster TVN. He beat ruling party candidate Ewa Leniart with 25.1%, and several right-wing candidates, including a Deputy Justice Minister Marcin Warchol, who was fronted by Law & Justice’s junior coalition partner.

“This is a red light -- we lost in the heart of the right-wing enclave,” Jan Maria Jackowski, a senator from Law & Justice, told TVN. “The coalition came into this election divided and I hope that we will draw the right conclusions.”

The three-party coalition government has for months been fighting over issues ranging from European Union policies to posts in state-controlled companies. On the other hand, there has been little appetite for the creation of what would be a left-to-center-right coalition that could have a shot at winning the next general ballot, which is scheduled for 2023.

Fijolek was backed by the Civic Platform, the Polska 2050 movement, the Peasants Party and the Left.

Rzeszow, with a population of almost 200,000, is the capital of the Podkarpacie region, which voted 62.4% in favor of Law & Justice in the 2019 parliamentary election. Fervently backed by public television, which is run by a former ruling-party lawmaker, the government remains broadly popular despite some erosion of support during the pandemic.

The election in Rzeszow was held as the previous mayor, 81-year-old Tadeusz Ferenc, resigned in February after nearly two decades on the job. Ferenc anointed Warchol, who ended up fourth with 9.3%.

The exit poll has a 2 percentage point margin of error and final results should be known on Monday.

(Updates with quotes and details from fourth paragraph.)

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