Portuguese citizens vote on Sunday in the country's general election, in which the current Socialist PM Costa is the favourite.
Polls opened on Sunday morning in Portugal's general election. The current Socialist PM, Antonio Costa, is running for re-election.
Costa, 58, formerly the mayor of Lisbon, is the race's favourite. If he wins another term, his victory would confirm Portugal's position as one of the rare European countries where Socialists are politically successful and where the far-right isn't rising.
Latest polls, published Friday, showed Costa's Socialist Party at 36 to 39%, far ahead of the centre-right Social Democratic Party at 25 to 30%. The Social Democratic Party is led by Riu Rio, 65, the former mayor of Porto.
Such a result, if confirmed, would renew the Socialists' grasp on the Portuguese Parliament, which counts 230 seats, but wouldn't offer them an absolute majority.
Costa would then need to form a coalition, probably with the left-wing Left Bloc, the Communist Party or the smaller party People-Animals-Nature.
Exit polls will be published at 20:00 CEST.