East or West?

The 6.75 million registered voters -- including more than 115,000 Serbs scattered across Kosovo, the Albanian-majority province which broke away from Serbia almost three months ago -- are choosing from 22 tickets.

The crucial choice, however, is between the ultra-nationalist Serbian Radical Party (SRS) and President Boris Tadic's pro-EU Democratic Party (DS), both tipped to win close to one-third of ballots cast.

"The May 11 elections are a form of referendum at which citizens will decide on whether or not Serbia... will be a member of the European Union," Tadic said in a pitch to voters at the end of a spiteful campaign.

With neither of the top parties expected to be able to form a government on their own, a three-way coalition will likely be needed to be forged.

King-makers or deal-breakers?

Outgoing Prime Minister Vojislav Kostunica's Democratic Party of Serbia (DSS) is expected to remain in position of the kingmaker despite its dwindling popularity, with the late Slobodan Milosevic's Socialist Party of Serbia (SPS) in tow.

Local observers said a coalition of SRS with DSS and SPS was the most likely outcome. Kostunica and SRS leader Tomislav Nikolic have wowed to prevent Serbia's closer ties with EU in protest at Western support of Kosovo's secession from Serbia.

"With the European Union, we should not negotiate about anything anymore, without it first clearly saying that Serbia is recognised as a whole," Nikolic told reporters after casting his ballot in Belgrade.

"The European Union will decide by itself whether it wants Serbia as a part of it or not. We want to join the EU, but Serbia is a united state within the borders recognised by its membership in the United Nations."

Mending ties

Milosevic's Socialist Party of Serbia (SPS) already said it would follow Kostunica, eight years after they were ousted along with Milosevic.

Kostunica has led the past two cabinets, since early 2004, despite never having the most seats in parliament and who would again hold the keys even if he wins the predicted 13 or so percent of votes.

Another pro-European group, the fiercely anti-Milosevic and pro-European Liberal-Democratic Party (LDP), has been tipped to be the fifth and final to clear the 5-percent hurdle of votes won to qualify for parliament, along with minority tickets.

EU watches closely

The parliamentary poll was called three years early after Kostunica's and Tadic's alliance disintegrated in the tug of war over Serbia's EU course in the aftermath of Kosovo's independence.

Some 40 nations, including the United States and all but a handful from the EU, have recognized Kosovo since its ethnic Albanian-dominated parliament declared independence on Feb. 17.

Russian opposition to Kosovo's unilateral move has so far made it impossible for Pristina to seek a United Nations seat, while Serbia -- whose constitution defines the southern province as an inseparable part of the country -- proceeded to open 295 polling stations in Kosovo for the Sunday election, despite opposition Kosovo Albanians.

The United Nations administration in Kosovo has branded the poll illegal although it has allowed the Serb minority to vote.

The traumatic secession of the southern territory -- viewed by most Serbs as the cradle of their history, culture and Orthodox Christian religion -- has buoyed support for the nationalists ahead of the elections.

In a move meant to woo voters disillusioned with the West, the European Union signed last week a pre-membership pact with Serbia. But this only added spice to a campaign that was marred by death threats against Tadic, as well as bitter mudslinging, counter-accusations and renewal of harsh nationalist rhetoric.

The first estimates of the outcome are expected from agencies processing a sample of polling stations a few hours after the voting ends at 8 pm.