Iraqi political leaders are urging Sunni and Shi'ite parties to end their boycott of parliament and return to discuss a new draft law on sharing the country's oil revenues.
The Sunni Accordance Front has been boycotting parliament to protest the ouster of the Sunni Arab speaker Mahmoud al-Mashhadani after a series of controversies.
The Sunni bloc said Thursday it will not return to parliament until the speaker is reinstated.
The Shi'ite bloc loyal to radical cleric Moqtada al-Sadr is also boycotting parliament to protest a bombing in June that damaged a revered Shi'ite shrine in the city of Samarra.
Tuesday, the Iraqi cabinet unanimously approved the new oil law, but parliament has yet to begin debate on it.
Sadr loyalists have rejected the draft, and Kurdish and Sunni politicians also expressed misgivings.
The law is designed to fairly distribute the benefits of Iraq's oil reserves among Iraq's Kurds, Sunni Arabs and Shi'ite groups.
Iraq's oil reserves - the world's third largest - are mostly in the Kurdish north and Shi'ite dominated south. There is little oil in Iraq's central region where Sunnis are in the majority and they fear the new distribution formula will treat them unfairly.