Updated

Hungarian Prime Minister Viktor Orban is expected to win his third consecutive term, and fourth overall since 1998, as voting stations opened across the country for the election of 199 parliamentary deputies.

Polls agree on the triumph of Orban's Fidesz party and its allied Christian Democrats, but a splintered opposition and Hungary's complex electoral system make the margin of victory hard to predict.

Orban's campaign has been based near exclusively on his unyielding anti-migration policies, though voters say they are more concerned with poverty, corruption and the country's underfunded health care system.

His main challengers are Gergely Karacsony, the candidate of the Socialist and Dialogue parties, and Gabor Vona from the nationalist Jobbik party.

Some 8.3 million Hungarians are eligible to vote, with preliminary results expected Sunday night.