FILE PHOTO: Iraqi Shi'ite cleric Moqtada al-Sadr, who's bloc came first, meets with Iraqi Prime Minister Haider al-Abadi, who's political bloc came third in a May parliamentary election, in Najaf, Iraq June 23, 2018. REUTERS/Alaa al-Marjani/File Photo

BAGHDAD (Reuters) - Populist Iraqi Shi’ite cleric Moqtada al-Sadr has invited his biggest political rival to work with him on ousting the country’s prime minister as thousands of anti-government protesters took to the streets for a fifth day.

In a statement on Tuesday Sadr, who leads parliament’s largest bloc, asked Hadi al-Amiri, leader of the second-largest, to help him introduce a vote of no confidence in Prime Minister Adel Abdul Mahdi.

“To answer brother Abdul Mahdi, I thought asking you to call an early election would preserve your dignity but as you have refused, I invite brother Amiri to work with me on withdrawing confidence from you immediately,” he said.

Sadr had on Monday asked Abdul Mahdi to announce early elections but the premier said on Tuesday he would not do so as it was up to parliament, not him, to do so.

In a statement addressed to Sadr earlier on Tuesday, Abdul Mahdi said that if the solution for Iraq’s ongoing crisis was his ouster, it would be easier and quicker for Sadr and Amiri to withdraw confidence and have a new government take over.

Abdul Mahdi came to power just a year ago after weeks of political deadlock as a compromise candidate between Sadr, who leads a populist alliance made up of his followers, communists, and other parties, and Amiri, the head of an alliance of Iran-backed Shi’ite militia leaders.

Mass protests driven by discontent over economic hardship and corruption have broken nearly two years of relative stability in Iraq. At least 250 people have been killed since the unrest started on Oct. 1.