"I vote 1,000 times yes, not only once, because I have not forgotten the mass graves and the torture and the killings," said Abdul Hussein Ahmed, 63, a laborer who emerged from a polling station in Najaf with purple finger aloft.

"Five members of my family were killed by Saddam and his people. But now, with this constitution, everyone is equal under the law," Ahmed said. In the north, where passage of the constitution with its federal system would enshrine the de facto autonomy Kurds there have enjoyed since the Persian Gulf War, Salih Saeed Mohammed, 64, blew on his ink-stained finger as he left a polling place. "This process legitimizes the fate of our nation," he said referring not to Iraq but to the Kurdish north, where many believe its establishment as a federal region will lead to independence.

When polls closed in the city of Sulaymaniyah, thousands of people poured into the streets among drivers pounding car horns and waving Kurdish flags.