By Justyna Pawlak

GARWOLIN, Poland (Reuters) - Poles vote in a presidential election on Sunday that the pro-European government in Warsaw says can revive its stalled democratic drive and its nationalist opponents see as a chance to set Poland on a path inspired by U.S. President Donald Trump.

Opinion polls show the liberal Warsaw mayor Rafal Trzaskowski, 53, an ally of the ruling coalition, as a probable winner, although most likely only after a runoff due on June 1.

Polling second to replace nationalist ally Andrzej Duda after his two terms, is amateur boxer and conservative historian Karol Nawrocki, 42, who is backed by the nationalist opposition Law and Justice (PiS) party. Far-right candidate Slawomir Mentzen, 38, is third.

Both are fans of Trump, with his Make America Great Again movement, and their anti-immigration stance and a crusade against "woke" liberal values.

The election coincides with a runoff presidential vote in Romania, where hard-right Trump admirer, George Simion, is favoured to win amid a surge of nationalism in Central Europe fanned by concerns over living costs, migration and security threats from Russia.

In Poland, Trzaskowski looks likely to beat back nationalist rivals, in part thanks to his shift towards the right in a bid to win over more conservative votes.

If he does, he has pledged to work with the government of Prime Minister Donald Tusk to undo changes to Poland's judiciary under PiS that critics in the European Union and at home said had eroded democratic checks and balances.

PiS lost its majority to Tusk's centrist coalition in an October 2023 election after nearly a decade in power, amid a wave of popular anger over its record on women's and minority rights. But Duda has used a presidential veto to block much of Tusk's reform efforts.

"The stakes in this election are as high as they were on October 15," Tusk said in parliament last month. "So I am hoping for mobilisation ... It's hard to govern alongside a hostile president, with all those vetoes."

In Poland, the president has the right to veto legislation and serves as a commander in chief, but has limited executive powers.

'MEDICAL TOURISM'

With the war in neighbouring Ukraine entering possibly a final stage after more than three years of fighting, Trzaskowski, Nawrocki, and Mentzen have all touted their credentials as wartime leaders.

All three promise to continue supporting Kyiv militarily but have differed on how much help should be given to refugees from Ukraine.

Nawrocki and Mentzen also oppose NATO membership for Ukraine, and emphasize that Poland's security interests lie with Washington, while Trzaskowski seeks a bigger role for the EU in handling the conflict and safeguarding Europe's security.

"We support Ukraine ... in its efforts to defeat post-Soviet Russia. That's obvious," Nawrocki said during a televised debate on Monday. "It is in the strategic interest of Poland to repel the neo-imperialist threat from Russia."

"As president ... I will build the Polish-American alliance and I will not agree for the EU to become a NATO substitute."

Echoing Trump's language and tapping into growing fatigue among voters, Nawrocki and Mentzen say interests of ethnic Poles should take precedence over those of Ukrainian refugees.

"They come from Ukraine, register with doctors, lengthen queues and then they go back home. It's medical tourism that we pay for," Mentzen said during a campaign event in February.

Despite a roughly eight-point lead over Nawrocki, Trzaskowski, who is polling at around 32%, could struggle in a runoff between the two, political observers say.

The son of a jazz musician, Trzaskowski has had trouble appealing to voters in rural areas, where Nawrocki is often seen as someone who better understands their struggles with high living costs and opposition to migration.

"Nawrocki is simply close to my heart ... Trzaskowski's smile is not genuine at all," said Anna Cieslik, 38, a resident of Garwolin, a small town east of Warsaw.

Nawrocki's support has fallen in recent weeks, however, amid allegations that he had lied on his wealth statement and hid an apartment he had acquired from a vulnerable pensioner.

(Reporting by Justyna Pawlak; Additional reporting by Anna Wlodarczak-Semczuk; Editing by Tomasz Janowski)