The Iraqi government's two main sponsors agreed early Wednesday to drop their support for embattled premier Adel Abdel Mahdi, overcoming their rivalry to resolve a political crisis sparked by widespread demonstrations.

The surprise rapprochement came as tens of thousands flocked to the capital's Tahrir Square to demand the government quit, the largest rally yet since protests erupted on October 1.

Populist cleric Moqtada al-Sadr, who leads parliament's largest bloc, has spearheaded calls this week for Abdel Mahdi's resignation and early parliamentary elections.

Iraq has been rocked by two waves of anti-government protests since the start of the month that have left at least 240 people dead
Iraq has been rocked by two waves of anti-government protests since the start of the month that have left at least 240 people dead AFP / -

But Hadi al-Ameri, the chief of second-biggest bloc Fatah and a leading commander in its armed Hashed al-Shaabi branch, had thrown his weight behind the government.

In an unexpected move, Ameri announced overnight that he and Sadr would "work together to achieve the people's demands".

He thus accepted Sadr's public invitation, issued hours earlier, to coordinate on a no-confidence vote in Abdel Mahdi, whom he dramatically called on to "Get out!" in a tweet.

Populist Shiite cleric Moqtada al-Sadr (driving) has backed anti-government protests despite being a key part of the administration
Populist Shiite cleric Moqtada al-Sadr (driving) has backed anti-government protests despite being a key part of the administration AFP / Haidar HAMDANI

Sadr and Ameri formed a tenuous alliance to bring Abdel Mahdi to power last year but have been increasingly at odds in recent months.

Their partnership was further strained when several Hashed offices were torched in southern Iraq last week during protests.

'One name'

Parliament is set to meet for a third consecutive day on Wednesday, after they agreed to explore early polls and constitutional amendments and demanded Abdel Mahdi come in for questioning "immediately".

Protestors have gathered on a key bridge linking their main rallying point to the sensitive Green Zone
Protestors have gathered on a key bridge linking their main rallying point to the sensitive Green Zone AFP / Jonathan WALTER

The premier has so far ignored those calls, and on Tuesday dismissed demands for early elections, instead challenging Sadr to find a political solution.

If a new government was formed, Abdel Mahdi wrote, it could begin work within "days, if not hours."

Sadr, who had just returned to his hometown of Najaf from neighbouring Iran, appeared to take up the challenge.

Protesters remain on the streets of Baghdad despite the government's efforts to quell the demonstrations
Protesters remain on the streets of Baghdad despite the government's efforts to quell the demonstrations AFP / -

As the politics played out online, the public demonstrations continued late into the night on Tuesday in Tahrir Square.

Blaring horns, fireworks and loud Iraqi music filled the plaza, Baghdad's focal point for demonstrations.

"They said we wouldn't be able to do anything. But even if we change one name, now we have a voice," said Youssef, a 33-year-old who was spending his sixth straight night in the square.

Protesters have defied army orders to clear the streets between midnight and 6:00am local time, occupying the square and multi-storey buildings there.

AFPTV / STRINGER

Late Tuesday, security forces unleashed volleys of tear gas at crowds massing on a key bridge linking Tahrir to the Green Zone, which hosts government offices and foreign embassies.

But the crowds seemed unfazed.

"We've started fighting over who can kick back the tear gas canister first," Youssef joked.

'Cycle of violence'

Rallies in Baghdad and across the south have swelled in recent days, defying curfews, threats of arrest and violence that has left more than 240 people dead and more than 8,000 wounded.

The first burst of protests starting October 1 left 157 people dead, mostly protesters in Baghdad.

At least 85 more have died in a second wave starting last Thursday, including at least one protester killed overnight in the Shiite holy city of Karbala, according to the Iraqi Human Rights Commission.

The Karbala violence has sparked condemnations from Amnesty International, who said "excessive and often lethal force" was used against protesters "in a reckless and utterly unlawful manner."

"The vicious cycle of violence must end," said the United Nations' top official in Iraq Jeanine Hennis-Plasschaer, urging a national dialogue to respond to protesters' demands.

Thus far, the government's reform proposals -- hiring drives, anti-corruption campaigns and more social safety nets -- have failed to appease the protesters.

The movement is leaderless and disorganised, but recently received a new push from Iraq's younger generation, with students and school children streaming onto the streets despite orders to return to class.

Trade unions representing teachers, lawyers and dentists have all declared strikes lasting several days.

About 60 percent of Iraq's 40-million population is under the age of 25.

"We don't want this government any more. We want a transitional government and constitutional change," another female protester said.

"I'm a teacher, I have a salary, I have a house -- but the young unemployed people are my brothers and relatives, too."

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