AFP - Iraqi MPs on Monday again delayed a crucial vote on a new electoral law intended to establish a more transparent system for polls due in January, amid disputes over the oil-rich province of Kirkuk.

Lawmakers are scheduled to vote on the draft law on Tuesday after inconclusive discussions over the bill, which would decide whether ballot papers in next year's election will show candidates' names or only party titles.

"We have not reached a final agreement on the electoral law because several problems remain, the most important of which is Kirkuk," parliament's deputy speaker Khalid al-Attiya said on the sidelines of Monday's debate.

The vote was originally slated to be held on Thursday, but last week was delayed until Monday.

Sami al-Askari, an MP in Prime Minister Nuri al-Maliki's Dawa Party, accused some parliamentarians of "blocking the vote on the law through their absence," ostensibly referring to the newly-formed Iraqi National Alliance (INA) coalition, several of whose MPs did not attend parliament.

The INA, a predominantly Shiite bloc, is challenging Maliki's multi-confessional State of Law coalition in the January 16 elections. Related article: Splits among Shiite and Sunni voters.

Kurdish demands to incorporate Kirkuk in their semi-autonomous northern region have proved a stumbling block in the debate on the new law.

Kirkuk's Arab and Turkmen communities remain strongly opposed to Kurdish ambitions, which also extend to parts of neighbouring provinces.

Article 140 of the Iraqi constitution calls for a referendum to decide Kirkuk's fate but it has been put off at the recommendation of the United Nations.

Earlier this month, MPs moved to retain the more opaque voting system used in 2005 but the move triggered the intervention of top Shiite cleric Grand Ayatollah Ali Husseini al-Sistani, who called for a change of heart.

The more open system advocated by Sistani was used in provincial elections in January which saw Maliki's allies take a majority of the votes in nine of Iraq's 10 Shiite-majority provinces, including the capital Baghdad.