Poland is voting to choose a new president with a wide gulf in the policies between the two frontrunners.
Parliament speaker Bronislaw Komorowski leads his rivals in the polls.
Voters appear to like his pro-business policies with between 41 and 51 per cent saying they support him.
Komorowski, a member of the ruling Civic Platform, also wants Poland to join the euro as soon as possible.
He has the backing of Polish Prime Minister Donald Tusk, an ally from his own party.
The death of Lech Kaczynski in an April air crash triggered this election and now his twin brother Jaroslaw is standing for the job.
Kaczynski, a former prime minister, is an ardent eurosceptic and opposes paring back Poland’s welfare state.
Tusk fears he would use the presidential veto to scupper government policies he disagrees with.
While the role is largely ceremonial, the Polish president also appoints several senior officials and has a say in foreign and security policy.
Ballot boxes will close at 6 pm GMT with exit polls expected to be published shortly afterwards.
If no candidate has won a minimum of 50 per cent of the vote, a run-off will be held on July 4.