Poles are voting in the final round of a cliffhanger presidential election race between the conservative incumbent Bronislaw Komrowski and an even more conservative challenger.

In his five years in office, the 62-year-old Komorowski has been popular and was easily expected to win re-election. But he narrowly lost in the first round of voting to Andrzej Duda, a little-known 43-year-old lawyer and member of the European Parliament with the Law and Justice party who waged an energetic campaign.

Polls in recent days have shown Sunday's race as being too close to call. The first round had a large protest vote for a rock star.

Exit polls will be published when polling stations close at 9 p.m. (1900 GMT), but final results are not expected until Monday at the earliest.