Iraqi lawmakers prepared for a gruelling round of talks on Thursday over a long-awaited pact setting a deadline for United States troops to leave the country.
Parliament had been scheduled to vote on the security agreement on Wednesday, but wrangling pushed it back a day.
It now is expected to meet before midday local time, subject to last-minute delay caused by negotiations between rival factions going on outside the house.
The landmark deal will pave the way for American troops to withdraw by the end of 2011, bringing in sight an end to a US military presence that has lingered on since the 2003 US-led invasion to topple Saddam Hussein.
Prime Minister Nuri al-Maliki's Shi'ite-led government and its Kurdish partners, who together hold most of Iraq's 275 parliamentary seats, probably could push the pact through by themselves, but would then struggle to sell it as representing the will of all of Iraq's fractious communities.
Once-dominant minority Sunni Arabs are concerned the US departure may curb their influence in Shi'ite-led Iraq and they have listed reforms they want adopted before they approve it.
Legislators agreed to meet a demand from the two main Sunni Arab blocs that the pact be put to a referendum next year.
But they rejected other conditions, including reforms that would cease the hunting-down and trying of former members of Saddam's Baath party and abolish the court that condemned the dictator to death - demands which have nothing to do with the US presence but which the Sunnis want in any bargain.
In Washington, Secretary of State Condoleezza Rice said a referendum would not delay implementation, which would go into force from the start of next year until a vote is organised.