WARSAW, Poland (AP) — Poles were voting Sunday in the final round of a cliffhanger presidential election race between the conservative incumbent Bronislaw Komorowski 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.

Duda's strong showing in a first round on May 10, which helped force a runoff, has exposed a rising disillusionment with the long-ruling Civic Platform party, which Komorowski is allied with. The party has governed Poland since 2007 and been marred by a string of corruption scandals. Its fortunes have also fallen somewhat with the departure from Poland of its former charismatic leader and prime minister, Donald Tusk, who is now the European Union president.

The first round had a large protest vote for a rock star, and political analysts say a majority of those votes will probably go to Duda. On the other hand, many people who didn't vote then are expected to vote this time, and many of those votes are expected to go to Komorowski.

The president has limited powers but the election is being closely watched as a sign for how Civic Platform and Law and Justice will fare in the more significant parliamentary election this fall.

Although both parties are conservative, the ruling Civic Platform party has a more liberal stance on some issues such as in vitro fertilization, and is more pro-European than Law and Justice, which has a nationalistic streak and has demanded more sovereignty from Brussels. Duda has called for higher taxes on banks and large supermarket chains, which are mainly foreign owned. He also said he wants Poland to retake control of the banks.

The Polish currency, the zloty, weakened in the final days of the campaign.

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.