Iraq's most influential Shiite cleric called Friday for Iraq to choose a prime minister before the newly elected legislature meets Tuesday, a political intervention that could hasten the end of embattled PM Nuri al-Maliki.

Grand Ayatollah Ali Sistani, who commands unswerving loyalty from many Shiites in Iraq and beyond, said the country's political blocs should agree on the next premier, parliament speaker and president within the next few days before the parliament convenes on Tuesday.

Under Iraq’s post-Saddam Hussein governing system, the prime minister has always been a Shiite while the largely ceremonial post of president is held by a Kurd and the speaker of parliament is a Sunni.

Sistani’s call could make it difficult for Maliki to stay on as caretaker leader, as he has since a parliamentary election in April. It means that he must either build a coalition to confirm himself in power for a third term or step aside.

Sistani’s message came after a meeting of Shiite factions, including Maliki’s State of Law coalition, failed to agree on a consensus candidate for prime minister.

Division among Sunnis

The Kurds also have yet to agree on a candidate for president and the Sunnis are divided over who should take the speaker’s role.

Negotiations over the political posts have often been drawn out. After the last election in 2010 it took nearly 10 months for Maliki to build a coalition to stay in office.

US officials have pressed the Iraqi government to become more inclusive, citing Maliki's purge of prominent Sunnis as one reason for the Sunni-led Islamist offensive that continues to seize control of Iraq's cities.

Maliki earlier this week rejected calls to form an interim “national salvation government” in a bid to ease the political divisions.

Divvying up the three posts in the four days before parliament meets, as sought by Sistani, would require leaders from each of Iraq’s three main ethnic and sectarian groups to commit to the political process and swiftly resolve their most pressing political problems, above all the fate of Maliki.

“What is required of the political blocs is to agree on the three [posts] within the remaining days to this date,” Sistani’s representative said in a sermon on Friday, referring to the Tuesday constitutional deadline for parliament to meet.

Maliki, whose State of Law coalition won the most seats in the April election, was positioning himself for a third term before the Islamist onslaught began.

Maliki's closest allies say he aims to stay in his post, but senior State of Law figures have said he could be replaced with a less polarising figure.

Sunnis accuse Maliki of excluding them from power, driving tribal groups to back a Sunni insurgency led by the Islamic State of Iraq and Greater Syria (ISIS or ISIL).

Maliki's tenure "effectively over"?

The president of Iraq’s Kurdistan region has also said Maliki should resign.

A Western diplomat, speaking on condition of anonymity, predicted that Maliki's tenure as prime minister was effectively over.

“It looks like the debate is whether it is going to be Tareq Najem, from inside State of Law, or someone from outside Maliki’s alliance,” the diplomat said, referring to Maliki’s onetime chief of staff and a senior member of his Dawa party.

“It is generally understood it will not be Maliki,” the diplomat said. “Security was his big thing, and he failed.”

One Iraqi man told FRANCE 24 that he doubted Maliki could stay in his post.

"Maliki has failed for eight years. He hasn't tried to solve our problems. How can he stay in power?" he asked.

Allies of Maliki said Sistani’s call for a quick decision was not aimed at sidelining the premier but at putting pressure on all political parties not to draw out the process with infighting as the country risks disintegration.

Over the past fortnight, militants have overrun most majority Sunni areas in northern and western Iraq with little resistance, advancing to within an hour’s drive of Baghdad.

Iraq’s million-strong army, trained and equipped by the United States at a cost of some $25 billion, largely evaporated in the north after the militants launched their assault with the capture of Mosul late on June 9.

Thousands of Shiite volunteers have responded to an earlier call by Sistani for all Iraqis to rally behind the military to defeat the ISIS insurgents.

The ISIS fighters, who aim to set up a caliphate spanning both sides of the Syria-Iraq border, consider all Shiites to be heretics deserving death.

(FRANCE 24 with REUTERS)