Baghdad, Iraq (CNN) -- The fate of Iraq's national elections hung in the balance Thursday as the nation's lawmakers failed to convene for an official session and adopt an election law, a move that could spark a delay in the upcoming vote.
Members of the 275-member Council of Representatives caucused over the proposed election law legislation but not enough of the politicians were present for a quorum. Lawmakers told CNN that they hope to convene as early as Sunday to consider the measure.
Elections are scheduled for January 16, and the constitutional deadline for the elections is January 31.
But Iraq's election commission will need at least 90 days after passage of the law to carry out elections, which U.S. and Iraqi government officials call a vital step in Iraqi efforts to solidify a democratic system in the post-Saddam Hussein era.
Officials fear that it would be impossible to get administrative needs in place for the election if the measure isn't passed soon. That would mean either a delay in the election or holding it under a law that was in effect for Iraqi elections several years ago.
A secure environment and political stability during and after the polls will be key as the U.S. looks to withdraw combat troops by next August, leaving 50,000 in advisory roles, and then withdraw all U.S. forces by the end of 2011.
The vote has been stymied by disagreements, particularly the electoral status of Kirkuk, the ethnically mixed northern Iraqi city, and the question of open and closed voting lists.
The disagreement in Kirkuk involves how to apportion votes among Kurds, Arabs, and Turkmens, the main ethnic groups there. Under the Saddam Hussein regime, Kurds were kicked out of Kirkuk and many Arabs moved in, a policy called "Arabization." But Kurds later returned to the city in droves after the Saddam regime was toppled.
There are sharp disagreements over which voter registries should be used in the elections, with the Kurds wanting a current one and the Arabs and Turkmens wanting registries from several years ago.
Kurds have long regarded Kirkuk as an integral part of Kurdistan and many want to be part of Iraq's autonomous Kurdish region. Arabs and Turkmens have their claims to the city and all the groups want their voices and votes to be fairly represented in the political system.
There had been talk that the Kurds were going to boycott Thursday's session, but several lawmakers said that hasn't happened despite the lack of quorum.
As for the lists, politicians disagree over the use of open lists that name candidates and closed lists that names parties. The law used in the 2005 election calls for a closed list.
President Jalal Talabani, Prime Minister Nuri al-Maliki and other political leaders -- members of the Political Council for National Security -- submitted two election law proposals, but disagreements over them remain among lawmakers.
U.S. Ambassador to Iraq Christopher R. Hill and Gen. Ray Odierno, the top U.S. military officials in Iraq, issued a statement on Thursday urging lawmakers to decide that "rules, procedures, and decisions" for the election apply only to that vote.
They argue it should not set precedents "for future political settlements related to Article 140, demographic change, disputed boundaries, or other contested issues," a specific reference to the Kirkuk question. Article 140 is the section of the country's constitution referencing the issue.
"The future of Iraq depends on the Iraqi leadership and people," the statement said. "We urge Iraq's political leaders to work out their differences and take swift action to do what is in the best interest of the Iraqi people so they may exercise their democratic rights on January 16, 2010."