Speaker Hajim al-Hassani, himself a Sunni, said the amended text, dealing with issues of federalism and former members of Saddam Hussein's Baath Party, would be submitted Sunday to parliament. The legislature, overwhelmingly Shiite and Kurdish, may vote on it or simply refer it to the voters.
Al-Hassani's comments indicated that negotiations on the new constitution had run their course. Barring a sudden change of mind by the Sunnis, the charter is likely to go to the voters over Sunni objections, setting the stage for a bitter political battle ahead of the referendum by supporters and opponents of the draft.
CBS News Correspondent Lara Logan reports that Sunni leaders are saying that they're going to campaign amongst their followers to vote no and defeat the constitution. They do have the power to do that if they can get enough votes, but the problem is they may not be able to get to the polling stations, Logan reports.
If the constitution clears parliament without Sunni blessing, it would be a blow to the Bush administration, which insisted all along that Sunni participation was critical to produce a document that was accepted by all communities.
Sunni Arabs are at the forefront of the insurgency and the Americans hoped the constitution would lure them away from the rebellion. But Sunni negotiator Saleh al-Mutlaq said the final draft fails to meet Sunni aspirations.
"We tell our people that we have fulfilled the duty that you asked us to do," al-Mutlaq told reporters Saturday. "We have sincerely done the job and now the matters are up to you. We want those who did not wake up until now to wake up. We want you to express your point of view but without violence" in the Oct. 15 referendum.
In other developments:
The move, the largest prisoner release to date, followed appeals by Sunni representatives to start releasing thousands of prisoners who have been languishing in the jail for months without being charged.
Meanwhile, written versions of the Shiite-Kurdish concessions were not released.
But Al-Hassani said the concessions, which were presented to the Sunnis on Friday, involved delaying details how to implement federalism, or the establishment of self-ruled regions, until a new parliament is elected in December. presumably with more Sunni members than the current one.
On the issue of purging former Baath Party members, many of them Sunnis, al-Hassani said "not every person who joined the Baath Party is a criminal. There are hundreds of thousands of people who joined the Baath Party for a reason or another and they come from all regions."
The vast gulf among Iraq's communities made the task of drawing up a document acceptable to all difficult. In a bid for consensus, President Bush telephoned a top Shiite leader, Abdul-Aziz al-Hakim, and asked him to make compromises with the Sunnis.
"A parliamentary agreement has been reached between the Kurdish coalition and the (Shiite) alliance on accepting the suggestions of the forces that did not take part in the elections (Sunnis) and it will be announced in parliament tomorrow," al-Hassani said.
Meanwhile, in an apparent attempt to mollify Sunni Arabs, the U.S. military on Saturday announced the release of nearly 1,000 security detainees from Abu Ghraib prison over the past several days.
The move, which had been in the works for some time, was the largest prisoner release to date and followed appeals by Sunni negotiators to the government to set free thousands of prisoners, most of them Sunnis, who have been languishing in the jail for months without being charged.
"I want to confirm that the releasing process is still going on and this number of 1,000 may be increased," national security adviser Lt. General Wafiq al Samaraei said. "The president and other governmental officials are interested in bringing the Sunni Arabs to the political process, and they will participate in spite of violence and terrorism."
With nearly 80 percent of the population, the Shiites 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 doesn't serve Sunni interests.
The political split between the two blocs pointed to fundamental differences on visions for the new Iraq. These included the country's identity, whether Iraq would continue as a centralized state or a federation based on religion and ethnicity and whether former Baath members, most of them Sunnis, had a future in public life.
Sunnis fear that federalism, demanded by the Shiites and Kurds, would not only establish a giant Shiite state in the south but also encourage future bids by the Kurds to expand their region into northern oil-producing areas. That would leave the Sunnis cut off from Iraq's oil wealth in the north and south.
Sunnis had insisted that the contentious issues of federalism and the fate of Baath party members be deferred to the next parliament, in which they hope to have more members. Sunni Arabs form an estimated 20 percent of the population of 27 million but won only 17 of the 275 parliament seats because so many Sunnis boycotted the Jan. 30 election.