Tehran  - Iran's ex-president Akbar Hashemi-Rafsanjani will lead the next Friday prayer ceremony on August 14 at Tehran university, Mehr news agency reported Saturday.

Rafsanjani's last appearance in the prayer ceremony on July 17 led to widespread protest demonstrations in several parts of Tehran against fraud in the June 12 presidential voting which led to President Mahmoud Ahmadinejad's re-election.

Besides former premier Mir-Hossein Moussavi and former president Mohammad Khatami, Rafsanjani is one of the main opposition figures.

Then trio have not yet acknowledged Ahmadinejad's re-election and all three demonstratively boycotted both the endorsement and swearing-in ceremonies of the president.

Rafsanjani, who was president from 1989-1997 and is still a major political figure, caused anger within the country's clergy when he said Iran was in a crisis.

The moderate cleric also called on the government to release all political prisoners as the first step to tackle the crisis.

While referring to former Iranian officials jailed due to their criticism against the president, he accused Ahmadinejad and the government "not to have even tolerance with our own people."

Following the criticism by Rafsanjani and other opposition figures and even conservative circles, some of demonstrators were released but the former officials are still detained and facing trial. (dpa)