The pro-European Union alliance led by Boris Tadic, Serbia’s president, won the advantage over hardline nationalists in snap elections on Sunday as voters demanded EU integration despite the loss of Kosovo.

The pro-EU list captured 38.7 per cent of votes and won 103 seats in the 250-seat parliament. The nationalist Radical party took 29.1 per cent and 77 seats, according to the Centre for Free Election and Democracy (CESID), an independent monitoring group.

Brussels welcomed the result, which in broad terms suggests a will by the largest ex-Yugoslav republic to digest the loss of Kosovo and aim for integration with the union. Dimitrij Rupel, foreign minister of Slovenia, which holds the EU’s rotating presidency, urged Serbian parties to form a governing coalition ”with a clear European agenda” without delay. ”This means that Serbia will move forward ever faster to membership of the EU,” he said.

President Tadic promised to put the divided Balkan country back on the path to economic reform and co-operation with United Nations war crimes prosecutors, under a new government to be formed as quickly as possible.

Yet he rejected any softening of Serbian objections to the independence of Kosovo, the ethnic Albanian-dominated breakaway state that declared independence on February 17.

“We have two strategic goals for Serbia: one is Serbia in the EU; and the other is territorial integrity of Serbia. The new government is never going to recognise the independence of Kosovo,” Mr Tadic said.

He also said he would not hand the premiership again to Vojislav Kostunica, the nationalist-leaning prime minister since 2004 whose smaller list, which came third in Sunday’s election, has held the balance of power in previous governments.

Forming a government will require a delicate balancing act with smaller parties – with such hard bargaining ahead that Mr Tadic would not yet name his preferred choice for prime minister. “Citizens of Serbia can celebrate. I’m not celebrating – I’m preparing for tough negotiations,” he said.

Despite the loss of seats for the Serb Radical party, rooms remains for a potential nationalist coalition with about half of total voter support.

Tomislav Nikolic, acting Radical leader, suggested the only stable coalition would bring his party together with Mr Kostunica’s list and the Socialists, who came fourth, to ”defend national interests”.

Mr Kostunica appeared amenable to such a grouping as he cited ”unbridgeable differences” with Mr Tadic over Kosovo and the EU. Alternatively, any pro-EU coalition must cobble together unlikely allies. In either scenario, the Socialists, the party of Slobodan Milosevic, the late autocratic president overthrown in 2000, will play a decisive role. Their price for cooperating with the pro-EU grouping would be to insist on higher pensions and more protective labour legislation that foreign investors might not like.

“The Socialists are the masters of the situation,” said Jovo Bakic, a political analyst in Belgrade.

Branko Ruzic, a senior Socialist official, promised to press for a “socially oriented and nationally responsible government” that excluded members who might accept Kosovo’s independence.

Working with the Socialists would force the pro-EU bloc to exclude the Liberal Democrats – the only list out of 22 that openly welcomed Kosovo’s secession – from government and fto operate as a minority coalition.

Mr Tadic would also have to persuade the Socialists to accept the controversial EU pre-accession agreement signed two weeks ago over the objections of nationalists both inside and outside the current, failed government.

Bozidar Djelic, the deputy prime minister who signed the Stabilisation and Association Agreement (SAA) on April 29, predicted such a “rickety coalition” could hold together for at least six critical months – long enough for for parliament to ratify the accord, and for the government to pass important economic reforms and improve ties with the EU.

Final election results are expected on Thursday.