Tens of thousands of nationalist supporters demanded the pro-Western government call early elections in Serbia at a rally Saturday, as their leader announced he was launching a hunger strike until the request is met.
The government has rejected the demand for early elections, saying they will be held after Serbia wins candidacy for EU membership in the autumn. Nationalists oppose that vehemently.
"This is my personal act, I am no longer taking any food or water," Toma Nikolic, the leader of the Progressive Party, told the crowd of about 50,000 people. "Serbia deserves sacrifice."
Nikolic remained for a while at the stage as the crowds dispersed. He later went into parliament, vowing to remain inside and challenging President Boris Tadic to react.
"He knows I am serious, he will have a sleepless night," Nikolic said.
There was no immediate reaction from Tadic, whose office is close to the rally site in central Belgrade. He previously has ruled out an early vote.
The opposition blames the pro-Western government for deepening the economic crisis and alleged corruption. It has demanded the government call early elections before next year, when they are due.
"We have had enough of the criminal regime, which has robbed all of Serbia," Nikolic's deputy Aleksandar Vucic said at the rally. "We want elections, they cannot stop that, popular discontent is growing day by day."
Opposition supporters _ many bused in from across Serbia _ carried national flags and banners calling for the fall of the pro-Western government. They booed and jeered at the mention of Tadic's name and shouted "Thieves!" and "Elections!"
Tadic has said in a statement that early elections would slow down his country's efforts to formally become a candidate for EU entry.
Serbia is still recovering from wars and international isolation in the 1990s. The country has recently moved forward in its bid to join the European Union, but the economic situation has worsened during the global crisis.
Nikolic, who met with Tadic on Thursday, said the opposition has offered compromise about the election date, but that this was rejected.
"This is my final offer, when something happens to me, just call the elections!" Nikolic said. "This is our struggle, the one we will win the hardest way."
Hundreds of riot police were deployed before the rally around government buildings in central Belgrade. No violence was reported.