The tension continues in Iran after a weekend in which Akbar Hashemi Rafsanjani breathed new life into the protests over the rigged presidential election with thinly-veiled criticism of his political rival, Supreme Leader Ali Khamenei.  Emboldened, the opposition led by Mirhossein Mousavi called for a new referendum not about the presidency but a vote on the legitimacy of the rule of Khamenei and the Guardian Council.  Khamenei did not wait until next Friday’s prayers to directly warn his opponents — including Rafsanjani:

Iran’s supreme leader issued a tough warning Monday to the opposition to back down after the movement called for a referendum on the government’s legitimacy, growing bolder in its challenge to the country’s clerical rulers.

The opposition has been energized by a show of support last week from former President Akbar Hashemi Rafsanjani, a key figure within the clerical leadership. Far from ending as the supreme leader has demanded, the conflict appears to be moving to a higher level, to a struggle within the leadership itself.

On Monday, opposition leader Mir Hossein Mousavi made some of his harshest comments yet at hard-liners and, implicitly, the supreme leader himself. Mousavi said they had insulted Iran’s people by claiming that the anger over June 12 presidential elections that exploded into massive protests was fueled by foreigners.

“You are facing something new: an awaken nation, a nation that has been born again and is here to defend its achievements,” Mousavi said during a meeting with families of those arrested in the postelection crackdown. “Arrests … won’t put an end to this problem. End this game as soon as possible and return the sons of the nation to the nation.”

Khamenei addressed his remarks today to the “elite,” which means Rafsanjani, who holds a key position in the Iranian government that could undermine his grip on power:

“The elite should be watchful, since they have been faced with a big test. Failing the test will cause their collapse,” Khamenei told a group of officials in a speech marking a religious holiday Monday, according to state radio.

“Anybody who drives the society toward insecurity and disorder is a hated person in the view of the Iranian nation, whoever he is,” Khamenei said, as Ahmadinejad and other officials sat on the floor beside him on stage.

Rafsanjani heads the Assembly of Experts, which has the power to remove Khamenei and replace him.  If Rafsanjani can convince a majority of that panel of mullahs to back him, he can oust Khamenei and take his place — and give Ahmadinejad the boot as well.  Last month, a couple of reports put Rafsanjani within reach of that goal, but not realistically able to conduct a wide-ranging reform that would have strengthened the role of democracy and limited the Guardian Council, as Rafsanjani reportedly wants in order to head off a revolution.

Since Rafsanjani still has not called a vote, it’s reasonable to assume he remains in the minority of the ruling clique.  He has not yet been arrested either, which means that his political support has not dissipated.  The referendum demand intends to embarrass the regime by not holding it and looking afraid, but Rafsanjani represents a real threat to Khamenei.  His vocal criticisms of Khamenei undermine Khamenei’s claims to divine leadership, and Rafsanjani’s support means that the hardliners have already split over it.  Khamenei’s choice of targets today shows what really worries him.