BELGRADE, Oct 29 (Reuters) - Serbia adopted its first constitution of the post-Milosevic era on Sunday after a last-minute surge to the polls saved a two-day referendum from failure due to insufficient turnout.
According to preliminary results from the respected national polling organisation CESID, 51.6 percent of the electorate of 6.6 million voted in favour of the constitution.
Overall turnout was 53.5 percent.
The document of 206 articles includes a preamble reaffirming Serbian sovereignty over the breakaway province of Kosovo, whose 90 percent ethnic Albanian majority ignored the vote, saying it made no difference to their demand for independence.
The previous constitution under the late strongman Slobodan Milosevic in 1990 stripped Kosovo its autonomy and ushered in a decade of oppression culminating in a war with NATO that ended with Kosovo being removed to United Nations control.
Debate on the content of the new constitution was scant ahead of the vote, and analysis of the result focused on how close it had come to failure by banking on the emotional pull of the Kosovo issue for Serbs.
"The magic figure of 3.32 million was passed at seven o'clock (1800 GMT)," said Zoran Lucic of the respected CESID polling organisation. Exactly 50 percent had voted with one hour of polling still to go, he said. Lucic's prediction of a final turnout of more than 53 percent was later proved accurate.
The bill's reference to Kosovo as an "inalienable" part of Serbia is seen as an eleventh-hour bid to block independence.
Critics say the clause was simply a fig leaf to help leaders duck responsibility for its impending loss, as well as a device to appeal to notoriously apathetic voters.
The United States says the clause changes nothing. The Kosovo Albanian demand for independence has the sympathy of Western powers whose troops took control in 1999 to stop Milosevic's army killing civilians in a guerrilla war.
Diplomats say the United Nations could grant Kosovo a form of independence in the coming months over Serbia's objections.
Serbian President Boris Tadic had warned that rejection of the constitution would plunge Serbia into "months, maybe years" of political uncertainty. Prime Minister Vojislav Kostunica said it would have had "bleak and unforeseeable consequences".
Kostunica's minority coalition is on its last legs, with the resignations of its key partners in the liberal G17 Plus party in his drawer. G17 has said this would ensure early elections as soon as the constitutional vote is over.
Elections were not due until the autumn of 2007.
Kostunica is now expected to call an early election, hoping for a stronger majority to ward off constant pressure from the ultranationalist Radical Party.
The threat of Serbia turning to the Radicals in a fit of anti-Westernism if Kosovo is made independent has been used by his government to scare Western powers insisting on the handover of top war crimes suspect Ratko Mladic, a hero to the Radicals.
The European Union has punished Serbia for failing to arrest him by suspending talks on closer ties, relegating the country to the bottom of the Balkan queue for eventual membership.
But some analysts said the lukewarm response to the Kosovo rallying call had exposed the nationalist threat as an empty one. (Additional reporting by Ljilja Cvekic and Zorana Vucicevic)