BAGHDAD, Iraq - Iraqi negotiators reached a breakthrough deal on the constitution Tuesday and at least one Sunni Arab party said it would now urge its followers to approve the charter in this weekend's referendum.
Under the deal, the two sides agreed that a commission would be set up to consider amendments to the charter that would then be put to a vote in parliament and then submitted to a new referendum next year.
The agreement would allow the Sunnis to try to amend the constitution to reduce the autonomous powers that Shiites and Kurds would have under the federal system created by the charter, negotiators said.
It boosts the chances for a constitution that Shiite and Kurdish leaders support and the United States has been eager to see approved in Saturday's vote to avert months more of political turmoil, delaying plans to start a withdrawal of U.S. forces.
The draft constitution has already been printed by the United Nations and millions of copies are being distributed to the public for Saturday's vote, so the new additions cannot be included. Instead they will be announced in the media, particularly on television, since many Iraqis are watching popular holiday programming during the current Islamic holy month of Ramadan, al-Dabagh said.
U.S. officials have pushed the three days of negotiations between Shiite and Kurdish leaders in the government and Sunni Arab officials, that concluded with marathon talks at the house of President Jalal Talabani late Tuesday.
A top Sunni negotiator, Ayad al-Samarraie of the Iraqi Islamic Party, said the measure would allow it to "stop the campaign rejecting the constitution and we will call on Sunni Arabs to vote yes." It was unclear if parliament would take a formal vote on the new deal with some lawmakers saying that measure may be read to the National Assembly on Wednesday.
Some other major Sunni parties were not present at the negotiations and it was not clear if they too would be willing to reverse their "no" campaigns.
The Sunni-led insurgents have demanded a boycott of the election and threatened those who would vote.
The announcement was the first break in the ranks of Sunni Arab leaders, who have been campaigning hard to defeat the constitution at the polls.
Ali al-Dabagh, a Shiite negotiator, said the sides agreed on four additions to the constitution that will be voted on Saturday that will allow for future amendments.
The central addition allows the next parliament, which will be formed in Dec. 15 elections, to form the commission that will have four months to consider changes to the constitution. The changes would be approved by the entire parliament, then a referendum would be held two months later.
Sunni Arabs are hoping to have a stronger representation in the next parliament and want to make major amendments to the constitution, particularly to water down the provisions for federalism, which Shiites and Kurds strongly support.
The other additions include a statement stressing Iraqi unity and another states that the Arabic language should be used in the Kurdistan region, along with Kurdish - issues important to the Sunni Arabs. The fourth underlines that former members of Saddam Hussein's ousted, Sunni-led Baath Party will only be prosecuted if they committed crimes.
Some moderate Sunni leaders once had positions in the Baath Party and fear being barred from politics by the De-Baathification process outlined in the constitution.
"The leaders of the political blocs have approved these additions and amendments and tomorrow they will be announced (read) to the national assembly," al-Dabagh said.