Followers of Iraq's top Shiite cleric often say he doesn't want a role in politics -- but that hasn't stopped him from intervening at every step in U.S. plans to hand power to the Iraqis. Even with the latest dispute over the interim constitution patched over, Grand Ayatollah Ali al-Husseini al-Sistani (search) is demanding his voice be heard.

The messy process of approving the charter made al-Sistani virtually another negotiator at the table with U.S. administrators and Iraqi politicians -- the most direct political role yet for the 75-year-old ayatollah, who rarely sets foot outside his house in an alley of Shiite Islam's holiest city, Najaf (search).

As in the past, he showed he could bend to political realities. But even when al-Sistani relents, the political realities have to bend as well.

After disrupting a planned signing ceremony three days earlier with his objections, al-Sistani gave Shiite members of Iraq's Governing Council (search) his consent for them to sign the new constitution Monday, convinced by the politicians of the need to maintain unity on the council.

But he quickly made clear what he didn't like about the document, issuing a fatwa, or religious ruling, that sharply criticized parts of it and cast doubts on its legitimacy. His words will strengthen Shiite leaders' demands and likely fuel fears among Sunni Arabs and Kurds of a Shiite push for domination of the future government.

It's a far cry from al-Sistani's "quietist" school of Shiite Islam. Unlike Iran's model of clerical rule, the quietist school dissuades clerics from a role in politics. Al-Sistani, an Iranian-born Islamic scholar, long symbolized that stance -- but that was under the brutal rule of Saddam Hussein, when lying low was a matter of survival.

Few Iraqi politicians feel al-Sistani -- respected as a "marja al-taqlid," or model for Shiites to emulate -- is turning toward the Iranian model. But some are clearly bristling at his intervention and see it as an attempt to promote the power of the Shiite majority.

"To say that the Shiite religious leadership is now meddling in politics is to understate the case," said Naseer Kamel al-Chaderchi, a Sunni Arab council member.

Al-Sistani's followers say his only motive is to protect Iraq's broader national interests -- unity and democracy -- at a time when there are no elected institutions and American occupiers hold enormous power over Iraqi politicians.

Indeed, the ayatollah has been the strongest voice calling for elections.

But a free election in Iraq will most likely mean a government dominated by Shiites. Al-Sistani's complaints over the new charter have focused on clauses that would allow the Kurdish and Sunni minorities to veto a permanent constitution even if approved by a Shiite majority.

His call for early national elections brought the most startling example of his influence. Tens of thousands of supporters marched in the streets of Baghdad and other cities in January demanding a vote.

The marches spelled the end for a key part of U.S. plans to hand over power to the Iraqis by July 1. And the show of power eventually drew the United Nations' special envoy, Lakhdar Brahimi, down the dirt path -- well worn now by political delegations -- that leads to the ayatollah's modest, cushioned sitting room.

Brahimi succeeded in convincing al-Sistani that an election before June 30 was not feasible, another sign of the cleric's pragmatism. But in the end, al-Sistani pulled out victories: The regional caucuses method the Americans had wanted to use to create a new government was dumped and elections were moved up to Jan. 31 at the latest, sooner than under the U.S. plan.

In the back-and-forth over the constitution, al-Sistani's role was more direct. Shiite politicians came to Najaf and held two days of talks to try to resolve his objections. One Kurdish council member even invited him to send a representative to negotiations in Baghdad over the charter, though it never came to that.

U.S. coalition officials depicted the talks as a matter of politicians consulting with leaders of their community -- as if he were just another prominent constituent.

But the Shiite leaders' need for one man's consent illustrates his power -- despite his Iranian birth and his reclusiveness. Even Ahmad Chalabi, a secular Shiite favored by the U.S. Defense Department, has moved closer to the cleric, apparently to build backing among the Shiite public.

Shiite council member Ibrahim Jaafari said al-Sistani, as a man of religion, "naturally does not interfere in the details of political work." But he acknowledged the power of the "marja" will endure.

"Even when there is an elected parliament that reflects the will of the Iraqi people, the marja'iyas will still have guidance to give and their views will continue to be respected," he said.