Poland is holding presidential elections on 18 May, which are seen as crucial for Prime Minister Donald Tusk and his pro-European government as they seek to push through their reform agenda.
The election is believed to be a battle between Tusk’s Civic Platform and the Law and Justice party, which has been backing incumbent President Andrzej Duda.
In power since 2015, Duda is due to step down after serving two full five-year terms.
Civic Platform’s candidate in this election is Rafał Trzaskowski, the incumbent mayor of Warsaw, who was defeated by Duda in the last presidential election in 2020.
He is predicted to be in a position to take first place with 30-35 per cent of the vote, and in the second round he should have just enough to defeat Karol Nowrocki, who is expected to come second with 20-25 per cent of the vote, according to polls.
A run-off between the two is expected to take place on 1 June.
Slawomir Mentzen, a candidate from the right-wing populist Confederation of Freedom and Independence party, is third in the polls with about 12 per cent.
At one point he was marching alongside Navrocki, but appears to have lost support after calling for a total ban on abortion, even in cases of rape, and an end to free university education.
An outspoken supporter of US President Donald Trump, Mentzen is active on social media and popular among young male voters for his combination of economic liberalism, political isolationism and anti-migrant rhetoric.
Polling stations opened at 8am Kiev time, voting will continue until 22:00, at which time exit polls are due to be published.
Final results of the election, in which 13 candidates are running, are expected on Monday.