The provincial elections — seen by Washington as a key step towards achieving national reconciliation among Iraq’s warring communities — aims to offer more powers to Iraq’s provinces, especially in economic projects.
Last week, the 275-member parliament voted on the law but it failed to pass because Kurdish lawmakers boycotted the session.
On Tuesday, the Kurds again boycotted the vote but parliament still managed to get the law passed, a crucial move if the electoral commission is to make the necessary preparations for polls to go ahead as scheduled on October 1.
The Kurds have opposed the bill because of disputes over how to constitute the provincial council of Kirkuk, the northern oil province claimed by both the Arabs and Kurds.
Parliament’s two deputy speakers — parliament Shiite Muslim Sheikh Khalid al-Attiya and Aref Tayfur, a Kurd — also boycotted the vote called by speaker Mahmud Mashhadani, a Sunni Muslim.
“The absence of a large section of representatives will harm the law and poison the political atmosphere,” Attiya told reporters.
Kurds have around 60 seats in parliament and the country’s president Jalal Talabani, is a Kurd.
Tuesday’s vote came three weeks after Iraq’s main Sunni Arab parliamentary bloc rejoined the Shiite-led government of Prime Minister Nuri al-Maliki after a near year-long boycott.
The move was seen as a major boost for reconciliation efforts as the boycott by members of the Sunni minority that once ruled in Iraq had dealt a blow to Maliki’s claims he was running a unity government.
Kirkuk, which lies 255 kilometres (158 miles) north of Baghdad, is claimed by both Arabs and Kurds, and a referendum to decide its fate was to have been held last December but was delayed after UN intervention.
Kurdish leaders agreed to a six-month postponement of the vote at the recommendation of the United Nations.
Article 140 of the Iraqi constitution stipulated that a referendum on Kirkuk be held by the end of 2007 to decide whether its oil wealth should be integrated into the autonomous Kurdish region.
Kirkuk has been gripped by ethnic tension since the US-led invasion of 2003, with Arab and Turkmen residents fearful they would be marginalised if the city were handed over to the Kurds.
Under the regime of ousted and executed dictator Saddam Hussein, Kirkuk was the scene of a massive population upheaval with tens of thousands of Kurdish residents expelled to make way for Arab settlers.
Today it has a mixed population of Kurds, Arabs, Turkmen and Christians, and since 2003 Kurdish politicians have encouraged Kurds to settle there