Bush tells Sunnis they must compromise to end deadlock over Iraq's constitution

"The Sunnis have a choice: do they want to live in a society that is free or do they want to live in violence?" Mr Bush told reporters in Idaho yesterday.

Attempts to introduce Iraq's new constitution remain mired in a sectarian stalematewith opposing sides declaring that they are not prepared to compromise. Hopes that a deal could be hammered out, after a three-day extension of the deadline, appeared to be fading with the Shia-dominated interim government saying yesterday that no significant changes would be allowed to the draft document already rejected by Sunni factions.

Voting on the constitution was postponed for 72 hours on Monday,the second extension in two weeks. But the head of the committee drawing up the document acknowledged that the extra time was unlikely to lead to any progress.

Sunni officials have warned that the country will be dragged into civil war if Shia and Kurdish parties use their majority in the National Assembly to vote through the constitution.

Yesterday they reiterated their vehement opposition to the federal structure proposed for Iraq's future government and highlighted other points of contention. As well as the wording on federalism, their objections include the banning of the Baath party from political activity and the failure to describe Iraq as an "Arab" nation. The Sunnis also oppose a clause which could allow the Kurds to secede from Iraq at a future date.

Last night the draft constitution appeared to be heading for a vote along sectarian lines. Amid renewed Sunni forecasts of a violent backlash, Shia leaders insisted that federalism remained the central tenet of a post-Saddam administration. The draft needs only a simple majority in the 275-member assembly to be ratified and the Shias have an overwhelming majority due to demographic advantage as well as a Sunni boycott of elections earlier this year. If approved, the constitution will be put to a referendum on 15 October where it can become defunct if any three of the country's 18 provinces reject it by two-thirds or more.

Sunnis are mobilising a campaign of opposition. Salih al-Mutlak, a senior Sunni official, said: "If it passes there will be uprising ... there will be a lot of trouble." Soha Allawi, another Sunni on the drafting committee, warned: "We will campaign among Sunnis and Shias to reject the constitution which has elements that will lead to the break-up of Iraq and civil war." But Jalal al-Din Sagheer, a leading Shia negotiator, added: "The only possible change now is that the Sunnis become convinced on federalism."

The drafting committee's chairman, Humam Hammoudi, put further pressure on the Sunni negotiators by stressing that, unlike the Shia and the Kurds, they were not elected but appointed following the election boycott. " Therefore, who can say they really represent the people on the street?" he said.

The adoption of the new constitution is a key plank of Mr Bush's exit strategy from Iraq, and US diplomats, led by ambassador Zalmay Khalilzad, have been strenuously pressing for it to be adopted.

Yesterday the Saudi government expressed concern over the impasse. The Saudis, who are Sunnis, have expressed concern about supposed Iranian influence over the largest Shia party in the National Assembly.

Meanwhile, seven people ­ five Iraqis, a US soldier and a US civilian contractor ­ were killed and 20 people injured when a suicide bomber attacked a joint US-Iraqi army base near Baghdad.

* Saddam Hussein met his lawyer and the chief judge investigating him yesterday and confirmed that the rest of his legal team had been sacked. Saddam's family have said they will pick lawyers to defend him against war crimes charges.