Shiite politicians plan to meet as early as Sunday at the urging of the country's top Shiite cleric to discuss the crisis over the nomination of Prime Minister Ibrahim al-Jaafari for another term, officials said.

Al-Jaafari's allies suggested the meeting would simply reaffirm his nomination, but others believed it could be the first step in finding another Shiite candidate for the top government post.

Opposition to al-Jaafari, including some within the Shiite United Iraqi Alliance, has deadlocked talks on a national unity government, which the U.S. believes is the best way to reverse Iraq's slide toward anarchy.

Jawad al-Maliki, a member of al-Jaafari's party, said representatives of all seven groups within the Shiite alliance would meet Sunday to discuss the nomination.

It appeared the meeting would be limited to top leaders or key figures from the alliance factions, rather than all 130 Shiite parliament members. The alliance's parliament members gave the nomination to al-Jaafari by a single vote in a ballot last February.

Several Shiite politicians said the meeting would be held at the urging of Grand Ayatollah Ali al-Sistani, who is anxious to prevent the al-Jaafari controversy from splintering the Shiite alliance.

Shiite politicians often turn to al-Sistani for direction in politically risky issues because of his stature within the Shiite community.

Sunnis and Kurds blame al-Jaafari for failing to stem rising sectarian violence between Sunnis and Kurds. The Americans and British have been pushing the Iraqis to resolve the impasse quickly. But al-Jaafari has refused to give up the nomination, and Shiite officials fear a move to oust him could split the alliance.

Al-Jaafari's allies suggested the meeting would be to affirm the prime minister's nomination.

Al-Maliki, the prime minister's ally, told Al-Arabiya television that talk of the alliance discussing other candidates was not true, and al-Jaafari's office issued a statement Saturday denying some Iraqi media reports that he was about to step down.

"So far, we still have one candidate...and that is Dr. Ibrahim al-Jaafari," al-Maliki said. "If there is an opinion to be discussed within the alliance, then it must be discussed through ... democratic means."

Al-Maliki said he understood that al-Sistani wanted the alliance to resolve the crisis "but I did not hear a call" for al-Jaafari to step down.

But he added that "all the possibilities are conceivable as part of the discussions tomorrow."

Khalid al-Attiyah, an independent member of the alliance, said several options were under discussion, including replacing al-Jaafari with Vice President Adil Abdul-Mahdi, who lost the February vote.

But al-Attiyah said al-Jaafari's Dawa party would oppose that move. Abdul-Mahdi is a member of the largest Shiite party, the Supreme Council for the Islamic Republic in Iraq.

Other proposals include naming another candidate from Dawa or someone not affiliated with either of the two big Shiite parties.