Serbia's Parliament speaker on Sunday officially called for a national referendum this month on a new constitution that would declare U.N.-run Kosovo is part of Serbia regardless of ongoing negotiations on the breakaway province's future.

Predrag Markovic set the plebiscite for Oct. 28-29, urging voters to come out in large numbers and support the new constitution, which underscores Serbia's opposition to possible independence for Kosovo. Independence, sought by the ethnic Albanian majority in Kosovo, is one of the options under discussion in U.N.-brokered talks.

Kosovo formally is a province of Serbia. But Belgrade has had no authority over the separatist region since a 1999 NATO bombing forced it to end a crackdown on Kosovo's ethnic Albanian separatists and pull out its forces.

Markovic signed off on the decision made by Serbia's parliament on Saturday, when lawmakers voted overwhelmingly in favor of the proposed constitution. The charter will replace one drafted in 1990 by the autocratic leader at the time, Slobodan Milosevic.

The hastily drafted constitution — agreed after a few weeks of consultation — will also define Serbia as an independent state for the first time since the breakup of Yugoslavia in the early 1990s.

At least 50 percent turnout and a majority of `yes' votes are needed in the referendum before the new constitution becomes effective. It was not immediately clear whether the more than 1 million ethnic Albanian voters would be included on the voting list.

The approval by 242 lawmakers in the 250-seat assembly was a rare case of consent among Serbia's diverse political parties, united this time in their opposition to possible secession of Kosovo. Most Serbs cherish the southern province as their state's original heartland

The new constitution has no direct influence on the international talks on Kosovo, but Prime Minister Vojislav Kostunica claimed it would "cement the truth that Kosovo always has been and always will be an integral part of Serbia."

Still, a few hundred government critics rallied in front of the parliament building during the assembly session, protesting that the new constitution might jeopardize Serbia's future by declaring Kosovo its own. The protesters, led by the opposition Liberal Democratic Party, announced a campaign for a referendum boycott.

In Kosovo, a separatist leader dismissed Serbia's move as a "provocation."

Kosovo's Deputy Prime Minister Lutfi Haziri, an ethnic Albanian, said that Serbia's latest move "represents a threat and a provocation ... which will become an obstacle in future normalization of relations between Serbia and an independent Kosovo."

International negotiators have said they want to conclude the talks by the end of the year, amid signs that Kosovo will be granted some form of independence.

Inclusion of Kosovo in the new Serbian constitution will effectively rule out Belgrade's consent to Kosovo's secession.