Some observers consider al-Sadr's position as mainly directed against Iran, while others believe it would be a test of strength between the two parties, particularly as Iranian Revolutionary Guards commander General Qassem Soleimani is in Baghdad for talks with his Shi'ite allies to salvage Tehran's influence in the country.
Shi'ite cleric Moqtada al-Sadr, whose Sairoon coalition (Marching Towards Reform) is emerging as the victor in Iraq's elections, invited Wednesday leaders of parliamentary blocs to meet ahead of forming a government of technocrats.
But Sadr's alliance tries to cross the ethnic and religious divide. Formal talks to form a governing coalition will begin after final results are announced this week.
Before the election, Iran publicly stated it would not allow Sadr's bloc - an unlikely alliance of Shias, communists and other secular groups - to govern.
AFP, quoting a source who attended both meetings, added that Soleimani will push for a broader coalition to re-unite former Iraqi prime minister Nouri Al-Maliki and the current PM Haidar Al-Abadi, both from the Shiite Daawa party.
A tally by Reuters of provincial results announced over the past three days shows Sadr's list leading, followed by Amiri, a close ally of Iran and a friend of Soleimani, and then outgoing Prime Minister Haider al-Abadi.
Saturday's election was the first since the defeat a year ago of the militants who had overran a third of Iraq in 2014.
The Quds Force, led by Soleimani, is the main foreign backer of the Badr organization, the backbone of the militias involved in committing massacres and sectarian crimes against Sunnis in Iraq.