BELGRADE, Yugoslavia (AP) _ Pressure mounted today on Serbian President Slobodan Milosevic _ even from his allies _ to recognize the democratic process and reinstate opposition election victories.

Student protesters, meanwhile, sought to circumvent a police ban on marching through Belgrade's streets by calling on people to drive into the city center and block it with cars.

Anti-government demonstrators who have poured into the streets for 40 days straight gathered in a carnival atmosphere Sunday, energized by signs that support for their pro-democracy movement is spreading.

Protest marches have been held in dozens of towns and cities almost daily since Milosevic overturned the results of Nov. 17 local elections that opposition candidates had won in Serbia, the dominant republic of Yugoslavia.

International mediators said Friday the opposition won elections in 14 communities, including Belgrade and Nis, and urged Milosevic to concede defeat.

A party in Milosevic's ruling coalition also was pressing for Milosevic to respect the findings of the Organization for Security and Cooperation in Europe.

The president of the New Democracy Party, Dusan Mihajlovic, wrote Milosevic asking that he declare what he stands for _ ``dictatorship, revolution or reforms'' _ the independent daily Nasa Borba reported today.

``We will never participate either in revolution or dictatorship. We are for privatization, full democracy and freedom of the press,'' party spokesman Zarko Jokanovic said today.

He said the party was considering all options and did not deny that it might leave the coalition. Though the moderate party is small, its departure could be a vital first crack in Milosevic's coalition.

The parliament of Montenegro, Serbia's junior partner in the Yugoslav federation, was to vote today on a resolution calling on the Serb leadership to respect the mediators' findings, said Momcilo Stojanovic, chief of Montenegro's Cabinet.

The premier of Montenegro had expressed solidarity with the protesters on Saturday.

Up to 50,000 supporters of the opposition coalition Zajedno rallied Sunday in downtown Belgrade, listening to an open letter from military representatives in six Serbian towns.

The army officers called on Gen. Momcilo Perisic, the Yugoslav army chief of staff, to tell Serbs whether he and the armed forces stand ``with the people, with the young generation, toward the future.''

``It has started! It has started!'' chanted the crowd, eager for signs that the military, police and the Serb media that have stuck with Milosevic might join their cause.

The authenticity of the open letter to Milosevic, his army chief and university students in Serbia's second-largest city, Nis, could not be confirmed. But independent media have reported the existence of such a letter, and the army _ a traditional bastion of support for Milosevic _ has not issued any denials.