Bulgarians are heading to the polls Sunday to elect their next president in a campaign centered on growing economic hardship and drone attacks on Black Sea shipping.

The vote will also be the first major test for the Moscow-friendly Progressive Bulgaria party of Prime Minister Rumen Radev after its election triumph in April.

Despite a record number of candidates, the race is expected to be decided in a runoff between incumbent President Iliana Yotova, backed by Radev's party, and former caretaker Prime Minister Andrey Gyurov, who is backed by pro-Western opposition parties.