An influential Shi'ite movement in Iraq led by radical cleric Moqtada al-Sadr says it wants former Prime Minister Ibrahim al-Jaafari to return to the job.
Al-Sadr's followers, known as Sadrists, voted in favor of Mr. Jaafari during a two-day referendum organized by the anti-American cleric.
Al-Sadr's group held the referendum to help it decide who to nominate as prime minister, after parliamentary elections last month yielded no clear winner.
The group rejected the top winners of the national election, including former Prime Minister Ayad Allawi, whose secular coalition captured just two more seats than incumbent Prime Minister Nouri al-Maliki and his Shi'ite-led bloc.
The group says Mr. Jaafari won 24 percent of the referendum vote with more than 1 million ballots cast last Friday and Saturday.
The referendum did not have government support and is not legally binding.
Both Mr. Allawi and Prime Minister Maliki failed to win a parliamentary majority, requiring them to try to form larger coalitions with other factions.
Mr. Maliki came a distant fourth in al-Sadr's referendum with 10 percent of the vote, while Mr. Allawi placed fifth with nine percent. The Sadrist movement dislikes Mr. Maliki because he ordered a military offensive against its Mahdi Army militia in 2008.
Al-Sadr's poll gave second place to Jaafar al-Sadr, a relative of Moqtada al-Sadr, with 23 percent of the vote. Write-in candidate Qusay Abdul-Suhail, a Sadrist lawmaker, took third place with 17 percent.
The referendum was open to all Iraqis, but it is not clear how widely the ballots were available outside of Sadrist strongholds in Baghdad and elsewhere.
Militants appear to have taken advantage of Iraq's post-election stalemate by carrying out a wave of attacks in and around Baghdad in the past five days, killing more than 100 people.
Washington says the violence will not alter its plan to withdraw combat troops from Iraq by the end of August.
Some information for this report was provided by AP, AFP and Reuters.