The party leader, former deputy prime minister Vuk Draskovic, said the exodus of Kosovo Serbs fearful of reprisals by ethnic Albanians could be stopped if political change was put in place.

The refugees demonstrating in Belgrade say their plight has been ignored by the authorities, and they will organise further protests on Monday in front of the parliament.

Vuk Draskovic demandes political changes

"We call on all people who have fled Kosovo and who are in Belgrade and the surrounding areas to gather in front of the Assembly of the Federal Republic of Yugoslavia tomorrow to express their protest at what has happened to us," said spokesman Svetozar Fisic.

The refugees say they feel betrayed by the government, and angry about the poor reception they have been given.

"Serbian government members should go [to Kosovo] and spend a month with their families, then they can tell me that it is safe," said one refugee.

Kosovo Albanians say they are taking back what is theirs

About 50,000 Kosovo Serbs have fled the province since the Yugoslav forces began withdrawing.

But most of them have been kept out of Belgrade, and forced to camp in car parks and fields until their return can be organised.

Draskovic warning

Serbian Renewal Movement President Vuk Draskovic said the departure of Serbs from the province could not be stopped without "fundamental and comprehensive political changes" in Serbia.

Jonathan Patteron: Belgrade has been slow to acknowledge the Serb exodus

His party has demanded the formation of a democratic and reformist government, now the Kosovo war is over.

Mr Draskovic warned that party members should be ready to do what was necessary if the government did not, in his words, come to its senses.

He also stressed that there would be no international financial aid for rebuilding Yugoslavia without reforms.

The BBC's correspondent in Belgrade, Jonathan Patterson, says the authorities are worried about the political implications of such a large influx of refugees.

Alexa Djilias: This is the end for Milosevic

Many observers say the government's failure to protect the Serb minority could herald the end of President Slobodan Milosevic's rule.

Political analyst Aleksa Djilas says although Mr Milosevic's political demise has been predicted in the past, this time it is more likely than ever before.

"Even the church has asked him to resign, and the church has never made such a direct appeal before. The church has great authority with very many Serbs," he said.