Slovakia's former prime minister Robert Fico will likely return to his old job after his left-wing Smer party trounced its opponents in Saturday's parliamentary election.

Preliminary results show Smer winning at least 86 of 150 seats.

Fico supporters threw him in the air and danced with him at a wild celebration at party headquarters in Bratislava.

Smer is expected to finish far ahead of the conservative SDKU party, led by outgoing Prime Minister Iveta Radicova. Final results are expected Sunday.

Fico, who was Slovak prime minister from 2006 to 2010, campaigned on promises to preserve the welfare system while raising taxes on corporations and the rich.

Saturday's election came two years early. A four-party ruling coalition collapsed in October when one of its junior members refused to back expansion of the eurozone's bailout fund.

The coalition was also involved in a scandal when a secret service wiretap revealed what sounded like a private financial group bribing government politicians.