Key political factions accused the premier of moving towards a dictatorship with the arrest of Iraq's electoral commission chief, a charge the prime minister denied on Saturday.
Faraj al-Haidari, head of the Independent High Electoral Commission (IHEC), was detained on Thursday for alleged corruption along with another of the body's members, Karim al-Tamimi.
Anti-US Shiite cleric Moqtada al-Sadr accused Prime Minister Nuri al-Maliki of being behind the arrests to obstruct the electoral process, joining other key Iraqi political actors who have made the same charge.
"The one who ordered the arrest is, to be precise, brother Nuri al-Maliki," Sadr said in a statement issued by his office in Najaf.
"Maybe the arrest is to the benefit of the brother prime minister, because in my opinion, he is working on postponing or cancelling the elections," said Sadr, whose movement has 14 MPs in parliament.
Haidari "was arrested while there are other people more important than him who are walking (free) and controlling peoples' destinies," said the influential Shiite cleric.
"The arrest of Haidari should be under the law and not under the power of dictatorship," he said.
Sadr's statement further ratchets up political tension, after the presidency of the autonomous Kurdistan region and a leading MP from the Sunni-backed Iraqiya bloc made similar accusations on Friday.
The Kurdistan presidency said the arrests were "targeting the independence of the electoral commission, and the goal behind them is to kill the democratic process by enhancing control over an independent institution."
It charged in a statement that "some of those controlling the government in Baghdad" were working to centralise power in the country, a charge that has been levelled against Maliki.
Haidar al-Mullah, a leading Iraqiya MP, told AFP: "The one standing behind this is the head of the State of Law coalition (Maliki), because he wants to send a message that either the elections should be fraudulent, or he will use the authorities to get revenge on the commission.
"Today, we skipped the phase when dictatorship is born, and now we moved to the phase when dictatorship is growing in the hands of the prime minister."
Maliki has previously faced charges of moving toward dictatorship, including from Sadr and also from Sunni Deputy Prime Minister Saleh al-Mutlak, who charged the premier was "worse than Saddam Hussein."
On Saturday, Maliki denied the dictatorship charges, saying post-Saddam Iraq had already witnessed transfers of power from government to government, and that it would again.
"Iraq cannot be governed by one person or one dictator or one tyrant, or one party," Maliki said.
"You already saw how power was transferred -- there was a first government, a second, a third and a fourth, and the fifth is on its way, and power will be transferred peacefully."
A statement on the website of the prime minister said that "we condemn all the... statements that seek to incite conflicts, instability and deliberately confuse the political situation."
It also said that "the prime minister was not aware of the arrest operation until after it occurred."
Haidari told AFP on Friday by telephone from a police station where he and Tamimi were being held that he believes the case against him is linked to the potential extension of the terms of current IHEC members that expire on April 28.
"This is one of the reasons which pushed Hanan al-Fatlawi and the State of Law to open this case again to prevent us continuing our job," he said, referring to Maliki's parliamentary coalition and an MP who is a member.