BAGHDAD - A close aide says anti-American cleric Muqtada al-Sadr is calling for an Iraqi referendum on who will be the next prime minister. The call comes days after Ayad Allawi, a secular Shiite who was heavily backed by Sunnis, was declared the winner of the March 7 election with 91 of 325 parliament seats, just two seats more than his closest challenger, Prime Minister Nouri al-Maliki with 89. Al-Sadr leads a Shiite religious party that won 39 seats and will likely be a kingmaker in any governing coalition. But his call is not likely to lead to referendum. The aide, who recently returned from Iran where al-Sadr had talks about forming a new government, spoke on condition of anonymity because of the sensitivity of the talks.