BAGHDAD — Iraqi lawmakers have only a day left to agree on a new bill that would enable the country to hold key parliament elections in January, according to remarks Wednesday by the country's election commission chairman.

The chairman, Faraj al-Haidari, said he warned the legislators that if they don't approve the election law by the end of Thursday, the country's nationwide vote will be delayed.

Any postponement in the Jan. 16 balloting could undermine the country's fragile stability and impact U.S. plans to withdraw troops from Iraq, now scheduled to ramp up after the vote. The possibility of the delay is additionally worrying because it is at times of political instability that violence tends to rise in Iraq.

"We informed the Parliament that if the election law is not legislated within 48 hours, it would be difficult and impossible to carry out the elections," al-Haidari said.

Iraqi lawmakers have been struggling to agree on the law, needed to carry out the vote. The key sticking point is the issue of who should be allowed to vote in Kirkuk, a disputed oil-rich city in the north that is claimed by both Kurds and Arabs.

Kurds consider Kirkuk a Kurdish city and want it part of their self-ruled region. But the Arab-led central government vehemently opposes anything that would remove Kirkuk from its control.

During the rule of former dictator Saddam Hussein, tens of thousands of Kurds were displaced under a forced plan to make Kirkuk predominantly Arab. Many Kurds have returned since the 2003 U.S.-led invasion of Iraq, but other groups claim Kurds have packed more Kurds into the city than before.

A referendum on the city's future, required by the constitution, has been repeatedly postponed.

The immediate dispute centers on voting rolls, listing who can vote in Kirkuk in January. Kurds generally have favored using a 2009 voter registry, which likely reflects the Kurdish population growth. Arabs generally prefer a 2004 voter registry, when the Kurdish population was not as large in Kirkuk.

As lawmakers intensely debate the draft election bill, a visit Wednesday by Iranian parliament speaker, Ali Larijani, raised cries from some Iraqi legislators of political interference by Iran.

"It is not an innocent visit," said Sunni lawmaker, Osama al-Nujaifi.

Many Iraqi political parties in Shiite-majority Iraq have strong ties to Iran. During Saddam Hussein's regime, many Shiite political and religious leaders sought refuge in the Persian neighbor. However, the connections with Iran have always been viewed suspiciously by Sunni leaders, and many Shiites as well, who worry that Iran has too strong an influence in Iraq.