The head of Iran's armed forces on Friday strongly attacked suggestions that Iran's supreme leader could be succeeded by a council, and warned of "plots" against the country's unity.
Registration opened on Thursday for February's election of the Assembly of Experts, the clerical body that appoints the supreme leader.
The assembly has the right to replace the supreme leader - currently Ayatollah Khamenei - but in practice no one expects that to happen. Most speculation is about how it would arrange the succession after Khamenei's death.
Last week Akbar Hashemi Rafsanjani, former president and influential member of the Assembly of Experts, said it would consider choosing a council of leaders, instead of a single ayatollah who rules for life.
"We never had council of leaders in history or a council that commands the army," said Hassan Firouzabadi, chief of staff of the armed forces, in a statement published by the Fars news agency.
"All the plots have failed, now they have resorted to the new trick of a council of leaders ... to undermine our progressive and stable leadership," he added.
"If the leadership becomes a council the country would suffer," he said. "And our strong unity against America, Zionists and imperial enemies would collapse."