The dissident Iranian cleric who was once designated as Ayatollah Khomeini's successor says the country's rulers may lose their legitimacy.
The elderly cleric wants to play a prominent role
In his first public speech for six years, Grand Ayatollah Hossein-Ali Montazeri said most people were dissatisfied and that the issue should be put to a vote.
Ayatollah Montazeri was released from house arrest early this year.
It is a decision the authorities may come to regret, says the BBC's Tehran correspondent Jim Muir.
About 300 students crowded into a small meeting room at Ayatollah Montazeri's house in the holy city of Qom about 130 kilometres (80 miles) south-west of Tehran.
Despite his poor health, the 81-year-old seems to have decided to break his silence to play a more public role, our correspondent says.
The cleric recalled the late Ayatollah Khomeini's dictum that the people should make their own decision about who rules the country.
"The same applies now," the cleric said, "the majority of our population is now dissatisfied with the ruling establishment. The matter should be put to popular vote."
Ayatollah Montazeri was also strongly critical of the longstanding crackdown by the hardline judiciary on liberal intellectuals and reformist publications, describing it as un-Islamic and a disgrace.
Although he was one of the authors of the Islamic Republic's constitution, Ayatollah Montazeri is not an enthusiast for religious control of politics.
This was the main reason for his house arrest after he criticised the current Supreme Leader Ayatollah Khamenei.
Students have protested against the regime
In his speech he argued that the Islamic seminaries should be independent and not funded by the state authorities.
It was for speaking his mind thus that Ayatollah Montazeri lost favour as Ayatollah Khomeini's successor in 1989, our correspondent says.
It is thought that the current authorities may have decided to lift the restrictions on him in January because they feared he might become a cause celebre if he were to die under house arrest, he says.