By Aleksandar Vasovic
BELGRADE (Reuters) - Serbia raised the possibility of a referendum on Thursday on an accord to end the ethnic partition of its former Kosovo province, a high-stakes gamble that could cost Belgrade talks on joining the European Union.
The April 19 deal between Serbia and its majority-Albanian former province won Belgrade a preliminary green light for accession talks this year, but the bloc wants progress on the ground before taking a final decision on the talks in late June.
The accession process would drive reform and help lure investors to Serbia's ailing economy. But the accord faces resistance from some 50,000 Serbs in northern Kosovo, a region bristling with guns and deep animosity.
Trying to mollify them, Serbia's government said it was prepared to hold a popular vote. The decision would depend on talks next week with Kosovo Serb leaders, Serbian Deputy Prime Minister Aleksandar Vucic told a news conference.
"If they pledge on Tuesday to accept the results of a referendum, the decision of the majority of the people, then we will be ready in 15 days and we'll put an end to that story," Vucic said after meeting a delegation of Kosovo Serb mayors.
Under the accord, the northern Serb pocket will be integrated into Kosovo's legal system five years after the former province, which is 90 percent Albanian, declared independence from Serbia with the backing of the West.
Hardline nationalists and the Serbian Orthodox Church have accused the government of betrayal, but there has been little sign of a major backlash.
According to the results of an opinion poll released on Thursday, 57 percent of Serbian citizens support the accord. Twenty-nine percent of the 1,180 respondents oppose it, polling agency Faktor Plus said.
Serbia lost control of Kosovo in 1999 after 11 weeks of NATO air strikes to halt the massacre and expulsion of ethnic Albanian civilians by Serbian forces trying to crush a guerrilla insurgency.
But Belgrade retained a fragile grip on the northern pocket, where Serbs have lived largely as part of the Serbian state.
Desperate for the economic boost of closer EU ties, Serbia last week agreed to cede control over the north, and won a preliminary green light for the start of membership talks with the 27-nation bloc, probably later this year.
Kosovo Serb leaders pledged to resist.
"We will continue our peaceful battle, because we are in the right," said Slavisa Ristic, mayor of the northern Kosovo municipality of Zvecan.
"We cannot accept a change of identity by force," he said, according to the Tanjug state news agency.
(Additional reporting and writing by Matt Robinson; Editing by Michael Roddy)