Tehran, Iran ? Iran began its first trial of the postelection crisis on Saturday, a mass court case against more than 100 activists and protesters accused of plotting a “velvet revolution” to topple clerical rule.

Some of the most prominent politicians of the pro-reform movement, including a former vice president, were among the defendants brought before the court in gray prison uniforms. A number of them delivered confessions, according to the Iranian media.

Coming days before President Mahmoud Ahmadinejad is to be sworn into a second term, the mass trial was part of the government’s efforts to choke off a persistent protest movement by Iranians who claim his June 12 re-election was engineered through fraud.

The protesters have presented the cleric-led regime with its biggest challenge since the 1979 revolution despite a brutal crackdown that has left hundreds imprisoned.

A prosecutor used Saturday’s hearing to press the government’s claims that the opposition is a tool of foreign enemies. He accused the three biggest opposition parties of receiving money from foreign non-governmental organizations as they plotted a government overthrow.

The charges, read out in court by the prosecutor from a 15-page indictment, included attacking military and government buildings, having links with armed opposition groups and conspiring against the ruling system, Iran’s official news agency, IRNA, reported.

Reformists denounced the trial and said the defendants had no access to lawyers.

The indictment described an alleged years-long plot by the top pro-reform political parties to carry out a “velvet revolution,” a popular, nonviolent uprising to overthrow the Islamic Republic similar to ones in Eastern Europe. The phrase comes from the peaceful 1989 Velvet Revolution that overthrew decades of communism in Czechoslovakia.

The prosecutor said the three main opposition parties had taken money from foreign NGOs and had sought to use the election controversy as an opportunity to carry out their plot, according to a transcript reported by IRNA. He claimed Israeli and Western officials have spoken in recent years of fomenting revolution in Iran.

“Based on the evidence obtained and well-founded confessions of the defendants, these events had been planned in advance, and stages of the velvet revolution were carried out in accordance with a time schedule,” the indictment said.

IRNA did not give information about how many defendants were in court, but the semiofficial Fars news agency said more than 100 defendants were present.

They included several prominent reformist opposition activists. Among them were former Vice President Mohammad Ali Abtahi, former government spokesman Abdollah Ramezanzadeh, former Vice Speaker of parliament Behzad Nabavi, former Deputy Foreign Minister Mohsen Aminzadeh and the leader of the biggest reformist party, the Islamic Iran Participation Front, Mohsen Mirdamadi.