Iran's leading dissident cleric, Grand Ayatollah Hossein-Ali Montazeri, has called for democratic reforms ahead of the country's presidential election.
Ayatollah Montazeri says the president should have more power
He said the president should have more power and the authority of the clerics should be limited to religious matters.
The constitution of the 1979 Islamic Revolution was being misused "as a tool to put pressure on people", he said in an interview with Reuters news agency.
He said a lack of democracy was putting off voters from the 17 June poll.
In a rare interview, the cleric, once designated as Ayatollah Khomeini's successor, said he did not expect Iranians to vote in large numbers.
"Some figures have power, while responsibilities have been given to the president," said Ayatollah Montazeri, 83, at his office in his home city of Qom. "That is why young Iranians do not want to cast their votes."
He described the constitution not only as flawed but he said it was being abused by those who wanted to put pressure on the people.
He said it should be amended to give the president control over matters of national interest including the military, the police and state media.
"There is a contradiction in our constitution," he said. "It gives a lot of responsibilities to the president without giving him enough authority.
"Responsibility and authority should come together. You cannot give responsibility to someone without giving him authority."
He said the authority of Iran's supreme leader, Ayatollah Ali Khamenei, should be limited to religious issues.
Ayatollah Montazeri was sidelined after criticising the regime in 1988 and was held under house arrest in Qom until 2003.