The Serbian parliament convened to discuss the ongoing negotiations on the final status of the UN-administered province.
"If today we make a decision that a new constitution of Serbia should incorporate the uncontested truth that Kosmet (the Serbian term for Kosovo) is a part of Serbia, we shall make a vitally important decision and the only possible one. We are thus sending an unequivocal message to the world that when it comes to Kosovo and Metohija, Serbia is bound only and exclusively by what is written in its constitution," the premier told the parliament, calling for the adoption of the new constitution by the end of this year.
He went on to say that "a decision on Kosovo will be made by the people at a referendum on the new constitution".
To take away 15 percent of Serbia's territory will undermine the structure of the current world and pose a serious threat to the stability of the entire region (southeast Europe), Kostunica warned.
Kostunica again criticised a statement by the UN diplomat and former Finnish President, Maarti Ahtisaari, who pointed out the collective responsibility of the Serbs for the war in Kosovo.
The Serbian premier labelled this as an unheard-of argument given by an international envoy due to lack of other arguments in favour of Kosovo's independence.
The co-ordinator of the Serbian negotiating team for the talks on Kosovo, Slobodan Samardzic, said that Belgrade should continue its engagement in the negotiations although the talks had not yet brought any results.
Participants in the parliamentary debate supported a motion for the speedy adoption of Serbia's constitution.
MPs of the Serb Radical Party (SRS) and the Socialist Party, which used to be led by Slobodan Milosevic, said that Serbia must persist in its opposition to Kosovo's independence and respect the positions of China and the Russian Federation on the matter.
The Democrats, led by the incumbent Serbian President Boris Tadic, and the G 17 Plus party urged for a realistic approach, and supported the Belgrade negotiating team's efforts in the talks on Kosovo's decentralisation.
The Serbian government moved a proposal to adopt a report and decision noting that Kosovo and Metohija should be granted "substantial autonomy" in the sovereign state of Serbia.
Kosovo's total population is estimated at between 1.8 and two million, with local Albanians accounting for 88 percent of the population and Serbs accounting for seven percent.
During the Socialist Federal Republic of Yugoslavia (SFRY), Kosovo used to be the southern autonomous province of the Socialist Republic of Serbia. With Slobodan Milosevic coming to power in Serbia, ethnic tension in Kosovo rose and local Albanians were subjected to the terror of his regime, which was why NATO launched air strikes against Serbia in 1999. All the time the number of local Serbs was shrinking as they were leaving for Serbia, while the portion of ethnic Albanians was on the rise.
By UN Security Council Resolution 1244 (adopted in 1999), Kosovo was in principle defined as an autonomous province within the former Federal Republic of Yugoslavia. Kosovo is presently run by its Provisional Institutions of Self-Government and the UN Interim Administrative Mission in Kosovo (UNMIK), while security is maintained by the NATO-led Kosovo Force (KFOR) and the Kosovo Police Service.