An Iranian woman walks past electoral posters of candidates of parliamentary elections, in central Tehran, Feb. 26, 2012. More than 3,400 candidates are allowed by the Guardian Council, to run in the March 2 elections. (Vahid Salemi/AP)

Under siege from international sanctions and threats of Israeli attack, Iranian leaders are calling for a massive turnout in parliamentary elections Friday as a rebuke to the country’s enemies and an endorsement of its political-religious system.

But behind the calls for unity as thousands of pre-approved candidates sweep aside their differences in their quest for the people’s mandate, the vote is expected to strengthen the hand of those who rule in the name of God: Iran’s supreme leader, Ayatollah Ali Khamenei, and the hard-line Shiite Muslim clerics who have come to dominate political life here.

At stake are all 290 seats in the Majlis, or parliament. Few surprises are expected; reformists have been largely sidelined in a purge that followed the disputed 2009 presidential election, and the current candidates have been vetted by a 12-member body of Islamic clerics and jurists — half appointed by the supreme leader and half by parliament.

With the elections essentially reduced to an establishment faceoff, posters all over Tehran are urging voters — including the increasingly apathetic urban middle class — to make the turnout a “nightmare for Iran’s enemies” and show they reject the “bluff” of sanctions and threats.

At the same time, however, the tight balancing act at the core of the Islamic Republic seems to be tilting away from the popularly elected politicians and more toward the nation’s unelected spiritual leaders. Away from the siege-mentality rhetoric and state TV interviews, at smaller campaign meetings in universities and mosques, prominent candidates now openly call for the “republican” side — direct elections — to be reduced to confirming divine rule, rather than challenging it with earthly demands of the people.

“Legitimacy to rule comes from God, and not from the people,” Shiite Muslim cleric and parliamentary candidate Mahmoud Nabavian told an audience of mainly conservative students during a debate Saturday. “A democracy does not befit our country, but a theocracy does.... The people are there to help those chosen by God.”

The remarks by the black-turbaned Nabavian, who belongs to a faction of hard-line clerics called the Stability Front, were met with confused applause from the students who had filled the wood-paneled auditorium of Tehran’s Sharif University of Technology.

According to its 1979 constitution, the Islamic Republic is far from a theocracy. The first articles say its political system is “endorsed by the people” and national affairs “must be administered on the basis of public opinion expressed by means of elections.”

For decades, dozens of popular elections had helped make Iran one of the more democratic nations in a region that, until the 2011 Arab Spring, was ruled almost entirely by dictators and kings. Two of those elections resulted in victories for Mohammad Khatami, a reformist cleric who served as president from 1997 to 2005.

But Friday’s elections reflect deep ideological change since that period. Politicians who called for more freedoms, drawing millions of votes, have been arrested and marginalized, while a new crop of hard-line clerics and Revolutionary Guard Corps commanders — who believe in rule by those they deem God’s representatives on earth — is gaining influence.

“We are witnessing the role of the people diminishing,” said Nader Karimi Joni, a columnist for newspapers critical of the government. “Our system is shifting toward getting its legitimacy from God.”

Proponents of this idea were instrumental in bringing President Mahmoud Ahmadinejad to power in 2005 and strongly defended him when millions of Iranians protested his reelection in 2009 before succumbing to a violent crackdown.

Now their representatives, united under the Stability Front banner, are widely expected to win seats in the new parliament. The front is overseen by Ayatollah Mohammad Taqi Mesbah Yazdi, an ambitious cleric widely regarded as Ahmadinejad’s spiritual guide and a strong promoter of a technocratic “Islamic government.” A rift between the two that surfaced last spring now appears resolved, as does a public quarrel between the president and Khamenei.

Mesbah Yazdi and Ahmadinejad have pushed the supreme leader increasingly to the forefront of Iranian politics, stressing his role as the nation’s top decision-maker. The president has apparently decided to avoid clashes and joined those placing ultimate responsibility on the shoulders of Khamenei. Most in the tightening power circle now also adhere to this idea.

For his part, Khamenei has stressed the importance of the people’s role, but in October he floated the idea of doing away with a directly elected president in favor of a prime minister selected by parliament. He said this should not limit the people’s influence.

“More and more, our supreme leader is becoming the center and pivotal power in running our country,” said Sadollah Zarei, a columnist for the hard-line Kayhan state newspaper. “He is firmly on the top of the pyramid. This makes our country strong.”

One dissenting note came from Ali Mottahari, an incumbent candidate and vocal son of one of the ideological fathers of the Islamic Republic. He warned that vesting all responsibility in Khamenei endangers the nation and argued that the supreme leader can be criticized like every other official.

“In the Middle ages in Europe, the Catholic Church was despotic, and this led to revolt,” Mottahari said in Saturday’s debate with Nabavian, his clerical opponent. “Here, too, in Iran are some who want to make our leader despotic. This is a great danger.”

Special correspondent Ramtin Rastin contributed to this report.