Hajim al-Hassani, the parliamentary speaker, announced yesterday that a draft constitution would be put before the legislature today, whether Sunni Muslim negotiators accepted it or not. But Sunni leaders said amendments agreed by Shia and Kurdish representatives did not go far enough, and urged voters to reject the draft in an October referendum.
Barring a sudden change of mind by the Sunnis, the stage is set for a bitter political battle ahead of the referendum when the bloodshed in Iraq is increasingly acquiring a sectarian character. Even the optimists who still describe the violence as an insurgency might be forced to acknowledge that Iraq is in the grip of civil war.
The apparent derailing of the Iraqi constitution is a severe blow to George Bush, who urged a senior Shia leader last week not to push the Sunnis to the brink. With nearly 80 per cent of the population, the Shias and their Kurdish allies are gambling that the draft would win approval in the referendum. But if two-thirds of voters in any three of the 18 provinces reject the constitution, it will be defeated.
Sunnis form a majority in at least four provinces, and clerics already have urged them to vote "no" if the draft does not serve Sunni interests.
The US freed more than 1,000 prisoners from the notorious Abu Ghraib prison yesterday in an effort to placate Sunnis, who are responsible for the bulk of attacks on American and Iraqi forces. But the setback over the constitution will step up pressure on Mr Bush from the US public, which increasingly wants a clear path out of Iraq.
Rival demonstrators were yesterday converging on Crawford, near the President's Texas ranch. Cindy Sheehan, mother of a dead US soldier, has set up camp outside the ranch and become a symbol for opposition to the war. Thousands of supporters were due to join her, while a pro-Bush roadshow was holding a rally nearby.
Two polls published last week suggested that Mr Bush's job approval rating is now at its lowest point since he began the presidency. A Harris poll put Mr Bush's rating at 40 per cent and suggested 58 per cent of the US public had a negative opinion of the President's performance. His approval rating in June was 45 per cent.
A poll for the American Research Group put his approval rating at just 36 per cent. Fifty-nine per cent of the people polled said the country was "seriously off on the wrong track".
In an effort to shift public perceptions, Mr Bush last week gave three speeches in as many days, vowing that America would not be pulling out of Iraq. "As long as I'm the President, we will stay, we will fight and we will win the war on terror," he said.
But experts say the situation in Iraq, where the number of US troops killed stands at a little under 1,800 and where tens of thousands of Iraqi civilians have lost their lives, is clearly not helping Mr Bush's numbers. Such poor polling is putting pressure on Mr Bush's officials in Iraq to try and obtain something that can be presented as "progress".
"I'd say 40 per cent of the opposition to Mr Bush is based on rising [petrol] prices. Americans are very unhappy about this. But the other 60 per cent is Iraq. People are very disillusioned," said Larry Sabato, professor of politics at the University of Virginia.
John Pike, director of the military research group GlobalSecurity.Org, said the monthly average for US troops being killed stood at around 75, a figure that had not moved.