Rafsanjani warned before Friday sermon

TEHRAN, Iran (CNN) - An Iranian lawmaker has warned powerful cleric Ali Akbar Hashemi Rafsanjani not to allow "the enemy" to take advantage of his highly anticipated sermon on Friday.

"After a month-long silence, the position of Hashemi Rafsanjani will be very important for those of all political inclinations, particularly those who are aiming at the (destruction) of the unity of the system," lawmaker Mohammad Karim Shahrzad said in a recent interview with Iran's state-run news agency, IRNA.

Shahrzad called on Rafsanjani to "announce the support of the Supreme Leadership as the highest authority" in his speech.

"The lack of cooperation by Hashemi Rafsanjani with the 9th Administration has caused great damage to the system, government and society," the lawmaker said, according to IRNA.

Rafsanjani, a former president and normally a frequent speaker at prayer services on Islam's holy day, has not appeared at the weekly sermon since the disputed June 12 presidential vote.

Rafsanjani is the most powerful backer of Iranian opposition leader Mir Hossein Moussavi. He heads the Assembly of Experts, the council responsible for appointing or removing the supreme leader, and has become increasingly vocal about the election outcome.