SOFIA, Bulgaria (AP) — Bulgarians are voting in the European Parliament elections after a series of scandals overshadowed the debate on key issues of the EU's future.

Voters on Sunday are casting ballots for their country's 17 seats in the 751-member European Parliament. The vote is seen as a test for the center-right party of Prime Minister Boyko Borissov, which suffered a setback after senior officials were involved in corruption scandals.

Latest surveys show only three parties, belonging to mainstream European political groups, passing the election threshold — the ruling GERB party, the Socialist party, and the liberal MRF.

Projections suggest the nationalist and far-right vote will be split between several smaller parties, which could prevent them from capturing seats in the EU legislature.