The socialists have emerged as kingmakers in Serbia’s parliamentary elections with the opposition right and ruling liberals almost tying for power.
It means both the Democrats and the Progressives will vie for Socialist support to see which can form the next government.
Both main parties are also set for a closely fought second round run-off for the presidency. Democrat incumbent Boris Tadic took a narrow one point lead in the first round over the Serbian Progressive Party’s candidate, Tomislav Nikolic.
Tadic is credited with steering Serbia towards EU membership although his party’s support has crumbled in Serbia’s economic downturn.
Right-wing Nikolic was formally an ultranationalist but has since broken away and is likewise pledging support for Serbia’s EU membership.
Serbia won EU candidate status in march and the bloc is currently deciding whether to open accession talks with Belgrade next year.
However voters had been expected to register their anger over the economic woes fulled by the crisis in the euro zone which is Serbia’s main trading partner.
The official parliamentary results are due out by Thursday at the latest.