Small, frail and in his 80s, he looks no match for Iran's tough regime. But Grand Ayatollah Hossein Ali Montazeri is made of steel. He wields considerable moral authority as the country's highest-ranking and most fearless dissident cleric, representing a potent challenge to hardline authorities who have tried and failed to silence him for two decades. He was once Ayatollah Khomeini's designated successor but was unceremoniously cast aside by the founder of the Islamic Republic, just months before his death in 1989, because the Grand Ayatollah had criticised human rights abuses by the regime. Since then, despite official harassment of his aides and a six-year period of house arrest, Grand Ayatollah Montazeri has remained the outspoken conscience of Iran's religious community, an advocate of democratic pluralism and foreign policy moderation.
"Montazeri has refused to go away and is today more vocal and explicit in his criticism than ever," said Anoush Ehteshami, an Iran expert and professor of international relations at Durham University in England. "If anything, his claim that he stands for freedoms and justice are even more important today," Prof Ehteshami said in an interview. Despite official attempts to marginalise Grand Ayatollah Montazeri, he enjoys a considerable following as a marja - or model for emulation one of the highest-ranking Shia theologians, easily trumping the theological credentials of Iran's Supreme Leader, Ayatollah Ali Khamenei, who succeeded Khomeini.
Last week, Grand Ayatollah Montazeri, 87, delivered the severest statement yet by a senior cleric following June's controversial election. Iran, he said, had become a "military regime", not the just Islamic government conceived during the 1979 Islamic Revolution, which he helped found. More worrying for the authorities, Grand Ayatollah Montazeri proclaimed that his fellow marjas - a small number of top religious figures who provide spiritual and personal guidance to millions of pious Shias had the responsibility to come out publicly against the regime and the "crimes" he said it had committed "in the name of Islam".
The events, he added, were a "warning bell" for the clerics, who have historically "given refuge to people against crimes and violations committed by governments." He continued: "The grand ayatollahs are well aware of their influence on the regime, and they know quite well the regime needs their approval for its legitimacy. They also know the regime is exploiting their silence." Hours later, three of Grand Ayatollah Montazeri's grandchildren were arrested for allegedly taking part in political rallies. Four sons of three other reformist clerics were also arrested in an apparent effort to intimidate senior clerics and silence the younger clerical generation. A reformist website reported yesterday that the authorities had forced Grand Ayatollah Montazeri to cancel his annual prayer meeting marking the end of Ramadan.
Even if Grand Ayatollah Montazeri's fellow grand ayatollahs do not respond to his rallying cry, his stinging rebuke of the regime makes it more difficult for the authorities to harness clerical support for their continuing suppression of the opposition. Some other prominent clerics besides Grand Ayatollah Montazeri have criticised the crackdown on street protests, but none in such blistering terms.
His position, however, is unlikely to become mainstream unless his colleagues speak out as forcefully. Iran's clerical class is generally cautious and conservative, but when they do intervene en masse, they have been a powerful force as they were during the 1979 Islamic Revolution. "Montazeri is not a lone voice. There are other clerics, some quite senior, who now stand alongside him," Mr Ehteshami said.
Some analysts see Grand Ayatollah Montazeri as the most influential opposition figure after Mir Hossein Mousavi, the man millions of Iranians believe was the true winner of June's elections. "Montazeri is far more influential in my view than [Mohammad] Khatami and [Medhi] Karrubi," said an Iran scholar and former seminary student in Iran's holy city of Qom, referring to the opposition's other main figureheads. "He [Montazeri] has no official position yet his power and moral authority hasn't declined," added the scholar, who declined to be named. "At the same time, he's not too radical. He wants reform, not a new revolution."
Others question how much sway Grand Ayatollah Montazeri has among the clerical class given his official isolation. "But there is no doubt that he has remained the conscience of Iran's religious community on issues related to civil and human rights," said Farideh Farhi, a leading Iran expert at the University of Hawaii. "His consistency and persistence on these issues even before he was removed from office is what makes his words potent and relevant in these times of blatant violations of citizens' rights," she said.
In June, Grand Ayatollah Montazeri declared that "no one in their right mind" could believe the official results of the presidential elections. "A government not respecting [the] people's vote has no religious or political legitimacy," he said. He also called for three days of mourning for those killed in the huge pro-democracy demonstrations that followed the elections, and for the release of prisoners.
Similar criticism of the regime more than two decades ago brought about his dismissal as Ayatollah Khomeini's heir apparent in 1989. Grand Ayatollah Montazeri's "sin" in Khomeini's eyes was that he had begun to urge a more open Islamic government and condemned the arbitrary execution of large numbers of dissidents after the 1988 ceasefire with Iraq. Grand Ayatollah Montazeri was put under house arrest in 1997 after questioning the unaccountable authority exercised by Ayatollah Khamenei.
In February 2000, he spoke out strongly against clerical interference in the government. He defended the principle of clerical supervision to guarantee that government policy and legislation conformed with Islamic principles. But he said Ayatollah Khamenei should submit himself to popular elections and be accountable and receptive to public criticism. Grand Ayatollah Montazeri suggested, too, that the Islamic republican constitution, of which he was a prime author, should be changed to give the then reformist president, Mr Khatami, control over the security forces and military rather than leaving them in the grip of the Supreme Leader.
Despite his defiance, Grand Ayatollah Montazeri was released from house arrest, unbowed, in January 2003 to a rapturous welcome by hundreds of supporters. It was believed the authorities were worried that the ageing cleric could become a focus for opposition groups in Iran if he died while under house arrest. On his release, he declared: "Just as I did during my detention, I will continue to talk about issues and act."