On a list of 228 candidates submitted by a powerful Shiite-led political alliance to Iraq's electoral commission last week, Abdul Aziz al-Hakim's name was entered as No. 1. It was the clearest indication yet that in the Jan. 30 election, with Iraq's Shiite majority likely to heavily outnumber Sunni voters, Mr. Hakim may emerge as the country's most powerful political figure.

Mr. Hakim, in his early 50's, is a pre-eminent example of a class of Iraqi Shiite leaders with close ties to Iran's ruling ayatollahs. He spent nearly a quarter of a century in exile in Iran. His political party, the Supreme Council for the Islamic Revolution in Iraq, was founded in Tehran, and its military wing fought alongside Iranian troops during the Iran-Iraq war. American intelligence officials say he had close ties with Iran's secret services.

Nonetheless, many Iraqis and American experts on Iraq believe those fears are overstated. They say Iraqi clerics are generally wary of the idea of religious government, partly because of an entrenched doctrinal opposition among Iraq's Shiite religious leaders to direct rule by clerics, and partly because they recognize that Iraq's Sunni Muslims would fiercely resist it.

In a BBC interview in London on Monday, Sheik Yawar cited reports that Iran had pushed up to a million people across the 900-mile border with Iraq in a bid to influence the elections, and that Iranian money was flowing covertly to Shiite religious groups competing in the election.

"There are some elements in Iran who are playing a role in trying to influence the elections," he said.

But American and Iraqi officials say that many of the migrants crossing the largely unmonitored border are Iraqi Shiite families that fled Saddam Hussein's repression, particularly after the failed Shiite uprising that followed the Persian Gulf war in 1991. Aid groups working on Iran's side of the border have said that tens of thousands of Iraqis have been forced to return home, and that the citizenship of many other migrants remains unclear, in an area where there have been unregulated flows of tribal Arabs for centuries.

Also weighing against the prospect of an Iranian-style theocracy in Iraq is that Iraqi clerics, unlike the ayatollahs who dominate the government in Iran, mostly belong to the "quietist" school of Islam that holds that clerics should not hold political power directly. A forceful exponent of that view has been Grand Ayatollah Ali al-Sistani, the most powerful Shiite cleric in Iraq - an Iranian by birth - who used his pervasive influence to push rival religious groups together in the political alliance Mr. Hakim now leads.

In his rare interviews, Mr. Hakim has also spoken out against clerics filling government posts, saying that they should project their influence from the mosques, not ministries.

According to rivals of Mr. Hakim within the Shiite alliance, the close ties he forged with Iran's ruling clerics during his exile have been maintained since he and others in the Supreme Council returned to Iraq after Mr. Hussein's overthrow.

Those sources say that Mr. Hakim's group and other parties in the alliance, including Dawa, are receiving political advice and financing from Teheran. American officials say that Iran, or at least powerful agencies controlled by Iran's supreme leader, Ayatollah Ali Khamanei, have backed a wide array of parties, militias and charitable groups that act as fronts for political activities here.

Mr. Hakim has said that his party is respectful of Iran, but independent of it. In an interview with The New Yorker magazine before the American-led invasion of Iraq, he said the group's forces "will never be used as a tool of any foreign power."

In addition, Iraqi and American officials say, the ethnic and cultural divisions that have carved deep historical fissures between Iran and Iraq militate against Iraq becoming a client state of Iran. Since Arab warriors conquered much of the Middle East 1,200 years ago, the land that is now Iraq has served as an Arab frontier. Iraq's Shiites, overwhelmingly Arabs, the officials say, have always formed a crucial part of the Arab world's front-line defenses against Persian ambitions, most recently when tens of thousands of Iraqi Shiites fought in Iraq's armed forces during the war with Iran from 1980 to 1988.

There are also bitter rivalries among Iraqi Shiites themselves, and within the religious groups with ties to Iran. Mr. Hakim's party suspects that the group loyal to Moktada al-Sadr, the Shiite cleric who has led uprisings against the Americans, is a likely suspect in the assassination of his older brother, Muhammad Bakr al-Hakim, in August 2003. For now, those rivalries have been held in check so that religious Shiite parties can band together for the elections, but, judging from conversations among the groups, few believe the truce will last long after the elections.

There is also tension between religious and secular Shiite parties. While Mr. Hussein focused much of his brutality on restive Shiites, his rule entrenched secularism, and many Shiites say they would fight rather than submit to the dictates of a harsh Islamic state.

"Eventually, the Iraqi people will have to decide: Do they want a secular democracy or a regime dominated by religious figures?" said Adnan Pachachi, the 81-year-old former foreign minister and a Sunni Arab. "A religious government - I have a feeling that the Iraqi people would not tolerate a situation like that for too long. I can assure you that a lot of Shia, I think a majority, do not want a government dominated by religious figures."

American and Iraqi officials said polls commissioned by the American occupation authority, and more recently by the interim government of Prime Minister Ayad Allawi, have shown that ordinary Iraqis, including Shiites, are deeply suspicious of Iran's religious leadership and strongly averse to a government dominated by religious figures.

"Groups too closely associated with Iran may well suffer," said one American official in Baghdad who has long experience in the region. In fact, the new Shiite alliance almost fell apart last week when some members complained about the prominence of groups with links to Iran.

Many American and Iraqi officials say the talk of Iranian influence here reflects what they call a more plausible fear: that Shiite dominance in Iraq, coupled with Shiite rule in Iran, would reshape the geopolitical map of the Middle East. The development would be particularly threatening to Sunni-ruled states that border Iraq and run down the Persian Gulf, the officials say, carrying as it would the threat of increasing unrest among long-suppressed Shiite populations.

"What they are really voicing is their angst over the transition from a Sunni-led state to a Shiite-led state," one Bush administration official involved with policy toward Iraq said after the remarks by Mr. Yawar and King Abdullah. "That touches emotional, religious and historic chords and signifies changes that they don't like. It's a big emotional hurdle for the Sunnis in the region to accept."

The concerns have rippled through the Shiite religious establishment, and prompted leading clerics to offer reassurances. In a sermon in Najaf on Friday, Sadr al-Din al-Qabani, an influential imam, addressed the point directly, suggesting that some Sunni politicians were trying to sow antagonism toward Iraqi Shites by summoning the specter of an Iranian-dominated Shiite government.

"Some of our Arab leaders try to deceive their people, telling them that if these elections go ahead it will be a victory for Shiites, and that a Shiite victory will eventually mean a victory for Iran," Mr. Qabani said. "But Shiites aren't a threat to anybody. After decades of suppression, all they seek is a restoration of their rights."