July 16, 2008 | By CAMPBELL ROBERTSON

BAGHDAD — The entire bloc of Kurdish lawmakers walked out of Iraq’s Parliament on Tuesday to protest a proposed provincial election law, contending that part of it was unconstitutional.

The walkout by roughly a fifth of Parliament’s 275 members delayed voting on the bill, which governs provincial council elections scheduled to take place across Iraq this fall.

The dispute could yet be resolved quickly, but it introduced more uncertainty into preparations for the nationwide elections. Parliament will meet again on Thursday to discuss the bill, several members said, and talks are continuing in small meetings.

The walkout underscores the political power struggle among the Kurdish, Arab and Turkmen populations in the oil-rich northern province of Tamim and its ethnically mixed capital, Kirkuk.

The Kurds, claiming an ethnic majority in Tamim, have pushed to postpone the provincial council vote until a census is taken, a special agreement is forged or a constitutionally mandated referendum is held on whether the city should stay under Baghdad’s administration or join the Kurdish regional government.

Under the Constitution, the referendum was scheduled to take place by the end of last year, but logistics and the security situation have delayed the process. Many Arab and Turkmen lawmakers have insisted that Kirkuk vote at the time of nationwide provincial elections. The originally scheduled date of Oct. 1 for those elections appears unlikely.

The Kurdish officials who walked out on Tuesday said they had been prepared to vote on the draft election law, with the understanding that the only point open on Kirkuk was whether to delay the election.

But attached to the bill was a separate power-sharing proposal, requested by more than 100 Arab and Turkmen lawmakers, to create a provincial council in Kirkuk of 10 Kurds, 10 Arabs and 10 Turkmens, with 2 more representatives from the region’s small Christian population.

The Kurds contend that this arrangement, which had a good chance of passing, would not reflect their numbers. “If you already pick the seats before the election, why vote?” asked Mahmoud Uthman, a member of the Kurdish bloc in Parliament.

Mr. Uthman expressed confidence that an agreement would be reached but said the Kurds would not show up Thursday if the proposal was not removed.

Kirkuk has been at the center of a custody battle for decades. In the 1980s, Saddam Hussein began trying to tip the city toward an Arab majority, kicking Kurds out of their homes and forcing Arabs from the south to move in.

Several steps, including a census, were outlined in the Constitution to arrive at a just arrangement for the region, but none have been completed, leaving an atmosphere of profound mistrust between the different peoples.

The Kirkuk question is just one of several issues in the proposed election law that have provoked significant debate. Others include whether to keep a 25 percent quota for women in provincial councils; whether to ban the depiction of religious figures and symbols in campaign materials; and whether to switch to an open list system of elections, under which voters can choose individual candidates rather than parties.

The walkout took place before any of these issues came up for discussion, but two seemed to have been resolved beforehand. A consensus has formed around an open list system, according to several lawmakers. And the Islamic Supreme Council of Iraq, a Shiite party, which was the only party to publicly fight the proposed ban on the use of religious figures, said last week that it was dropping its resistance at the request of Shiite clerics.

Reporting was contributed by Suadad al-Salhy, Abeer Mohammed and Riyadh Muhammad from Baghdad, and an Iraqi employee of The New York Times from Kirkuk.