Iranian opposition leader Mir-Hossein Moussavi confirms to attend the prayer ceremony at Tehran University led by former president Akbar Hashemi Rafsanjani.

It will be his first official public appearance since last month's disputed presidential election.

For the first time in Iranian history, the Friday prayer ceremony at Tehran University is expected to turn into a podium for the Iranian opposition, Fars news agency reported Thursday.

I will join the lines on Friday as I feel obliged to respond to the call of companions on the path to protecting rights to a noble and free life, Mousavi said on his website Wednesday.

Mir Hossein Moussavi, 67, who was Ahmadinejad's closest rival in the June 12 election, has charged that the vote was rigged and dismissed the next government as illegitimate.”

Moussavi has reportedly decided to form a coalition front for continuing his protests against the Ahmadinejad government.

Officials said that thousands of Moussavi supporters are expected to show up at the prayer ceremony and use the opportunity to accuse the president of his election fraud.

The people should be careful not to create unsuitable scenes at the Friday prayer, said the intelligence chief Gholam-Hossein Mohseni-Ejei.

The authorities rejected charges of vote fraud.