NAJAF, Iraq — With religious Shiite parties poised to take power in Iraq's new national assembly, leading Shiite clerics are pushing for Islam to be enshrined in the new constitution, governing such matters as marriage, divorce and family inheritance.

On other issues, opinion varies, with the more conservative leaders insisting that Shariah, or Islamic law, be the foundation for all legislation.

Such a constitution would be a sharp departure from the transitional law that the Americans enacted before appointing the interim Iraqi government led by Prime Minister Ayad Allawi. One focus of the U.S. effort then was to secure equal rights for women and minorities. Under Shariah, for instance, daughters would receive half the inheritances of sons.

But in the national assembly, the U.S. influence will be much reduced.

When the interim law was written in early 2004, U.S. officials persuaded Iraqi drafters to designate Islam as just "a source" of legislation. That irked senior Shiite clerics, who, confident they have a popular mandate from the elections, are advocating for Islam to be recognized as the underpinning of the government.

The clerics' demands underscore the biggest question surrounding the new government: How Islamic will it be?

Compromises possible

Many factors could force the clerics to compromise their vision. The alliance of Shiite politicians in the national assembly could splinter as its members vie against one another for power and trade favors with rival politicians like the secular Allawi and the Kurds, who are Sunnis. Too strong a push for a Shiite religious state could also prompt violent opposition from Sunni Arabs, the formerly dominant minority that already feels disenfranchised, or from the Kurds, who can exercise veto power over the new constitution.

Shiite politicians, recognizing a possible backlash from secular leaders and the Americans, have publicly promised not to install a theocracy similar to that of Iran, or allow clerics to run the country.

But the clerics of Najaf, the holiest city of Shiite Islam, have emerged as the greatest power in the new Iraq. They forced the Americans to conform to their timetable for a political process. Their standing was bolstered in last Sunday's election by the high turnout among Shiite voters and a widespread boycott by the minority Sunni Arabs. Now the clerics will wield enormous behind-the-scenes influence in the writing of the constitution by their coalition built around religious parties.

"The constitution is the most dangerous document in the country and the most important one affecting the future of the country," said Alaadeen Muhammad al-Hakim, a son of and spokesman for Grand Ayatollah Muhammad Said al-Hakim, one of the most senior Shiite clerics in Iraq.

Iran model rejected

The leading Shiite clerics say they have no intention of taking executive office and following the Iranian model of direct government by religious scholars. But the clerics also say that the Shiite politicians ultimately answer to them and that the top religious leaders, collectively known as the marjaiya, will shape the constitution through the politicians.

"The opinion of the marjaiya will be raised through its representatives in the national assembly," said Sheik Abbas Khalifa, a senior aide to Ayatollah Muhammad Yacoubi, one of the most politically active clerics in Najaf. "The first thing the marjaiya wants to see in the constitution is respect for everybody and maintenance of Islamic identity."

Though the alliance could be threatened by power struggles, Grand Ayatollah Ali al-Sistani, the most powerful of Iraq's Shiite clerics, will urge the politicians to work together in writing the constitution, clerics say.

"Sistani and the other grand ayatollahs will press for as much Shariah — or Islamic law — as possible in Iraqi law," said Juan Cole, a history professor and specialist in Shiite Islam at the University of Michigan. "They can afford to be patient if they can't push through everything now."

Opposition to equality

The clerics generally agree that the constitution must ensure that no laws passed by the state contradict a basic understanding of Shariah as laid out in the Quran. Women should not be treated as the equals of men in matters of marriage, divorce and family inheritance, they say. Nor should men be prevented from having multiple wives, they say.

"We don't want to see equality between men and women because according to Islamic law, men should have double of women," said Muhammad Kuraidy, a spokesman for Yacoubi. "This is written in the Quran and according to God."

Khalifa said the ayatollah wants the constitution to make a clear break from the transitional law. "It just said that Islam should be respected. But we want a legal article that states frankly that no laws should violate Islamic law."