Poland's President Bronislaw Komorowski and his challenger in a close election are facing off in a tense debate.

The debate is a final chance ahead of Sunday's balloting for the contenders to sway voters who still haven't decided if they want to re-elect Komorowski or replace him with Andrzej Duda, a 43-year-old lawyer and member of the European Parliament.

Komorowski, 62, has been a popular president and was long expected to easily win re-election. But now he appears to be suffering from a general disillusion among voters with the ruling Civic Platform party, which he is allied with.

At the start of the debate Thursday, Duda walked over to Komorowski and placed a small Civic Platform flag on his podium to remind voters of his links to the party.