Iraq's political turmoil deepened last night when the ruling Shia and Kurdish coalition failed to win Sunni Arab support for a new constitution by a midnight deadline.
A planned session of parliament was abandoned amid confusion over whether a draft presented on Monday would be amended to allay the concerns of Sunnis, a restive minority driving the insurgency. Sunni leaders warned that Iraq would take a step towards full-scale civil war unless the draft dropped federalism.
Last night the Iraqi parliament's speaker, Hajim al-Hassani, announced a one-day extension to talks minutes after the deadline had expired.
Government spokesman Laith Kubba said Shias and Kurds had offered to dilute or delay aspects of decentralised rule, a concession which Sunnis seemed to be considering. But Mr Kubba said he expected them to reject the compromise, ending the talks. This would pitch the ruling alliance of Shias and Kurds into a potentially explosive referendum battle with the Sunnis.
"Further extensions are not going to alter the fact that it is impossible to reconcile very differing views on which way Iraq should go, so there is no point in having further extensions," said Mr Kubba.
It seemed likely the draft would be put to a referendum in October. If two-thirds of voters in three of Iraq's 18 provinces vote No, the constitution fails. Sunnis, a majority in four, are racing to register voters.
Mr Kubba told the BBC he doubted the constitution would pass a referendum. "My personal judgment is that it will not. We think a clear No vote is a healthy sign. Even if it means turning down the draft constitution that's still okay... A clear Yes or a clear No is what the country needs."
But rejection in October would be a devastating setback for the Bush administration, which has pushed hard for signs of political progress to deflect growing domestic criticism about US involvement in Iraq.
Mr Kubba said if a compromise deal did emerge today, parliament's authorisation for an amended text would not be needed since it had received and implicitly accepted most of the text on Monday.
No vote was taken then, and many assembly members had expected to vote yesterday - prompting accusations that negotiators were cutting corners to salvage a deal.
The disarray came on the heels of bloody clashes between rival Shia militias which underlined the febrile mood within and between the main sectarian and ethnic groups.
The Mahdi army of Moqtada al-Sadr, a radical cleric who led two uprisings against US-led forces last year, fought street battles with members of the Badr organisation in the Shia holy city of Najaf and four other towns in the south. They exchanged rocket and machine-gun fire, leaving at least six dead and dozens injured.
Violence eased when Mr Sadr called a press conference in Najaf and pleaded for calm, urging his followers to spare the blood of other Muslims and to return home.
The clashes exposed a power struggle between Mr Sadr, who commands loyalty among many poor Shias, and the political wing of Badr, the Supreme Council for the Islamic Revolution in Iraq (Sciri), the largest Shia party in the government.
Tension between the two has worsened over Sciri's push for the constitution to allow an autonomous region in the Shia south, something Mr Sadr fears will leave Iraq vulnerable to disintegration and Iranian meddling. Sunnis share the hostility to federalism, fearing they will be left stranded between Kurdistan in the north and a Shiastan in the south, leaving the once dominant minority in the centre with no oil and a weak government in Baghdad.
Having largely boycotted the January election, Sunnis were powerless to block the draft constitution in parliament but US diplomats, among others, lobbied the Kurds and Shias to bring them on board.
Imposing a constitution they dislike would risk fuelling the insurgency.
- (Guardian Service). Additional reporting AP.