BAGHDAD — The two front-runners vying to become Iraq’s next prime minister failed to get the support of an influential Shiite movement in results from a poll released Wednesday, further muddying the political situation following inconclusive March elections.

Instead, the bulk of supporters of anti-American cleric Muqtada al-Sadr, who has emerged as a kingmaker, said he should back Shiite politician Ibrahim al-Jaafari, who was interim prime minister from 2005 to 2006. Nearly as many cast ballots for one of al-Sadr’s relatives.

The Sadrists held the informal weekend poll after former Prime Minister Ayad Allawi’s secular bloc won just two seats more than incumbent Nouri al-Maliki’s coalition in March 7 parliamentary elections. With both sides far short of the majority needed to govern alone, the candidates are now scrambling to muster the support needed to form a government.

Al-Sadr became key to those efforts after his followers won at least 39 seats in the 325-seat parliament, up 10 seats from their current standing. That makes them the largest bloc within the Iraqi National Alliance, a Shiite religious coalition that placed third in the race.

Al-Sadr’s spokesman Salah al-Obeidi announced left open whether al-Sadr would follow the guidance of his supporters in the course of negotiations, which are expected to take months.

The poll was widely viewed as a way for the cleric to give himself the opportunity to back someone other than al-Maliki, under the guise of following the people’s will.

Al-Maliki and Allawi received only 10 percent and 9 percent of poll votes respectively.

Al-Sadr’s relative Mohammed Jaffar al-Sadr got 23 percent, senior Sadrist politician Qusay al-Suhail got 17 percent, and a handful of others split the remainder of the ballots.