Iraq's Sunni Arab vice president vetoed part of a key election law Wednesday, a move that could delay national polls slated for January even as the top US commander in Iraq said the timetable for American troop drawdown is on track. The veto, slammed by Iraq's Shi'ite prime minister as a threat to democracy, will most likely delay the vote since parliament must now discuss Vice President Tariq al-Hashemi's demands and take a vote on them, a process that could take days or even weeks given the legislature's fractious nature and its track record. Already, the country's election commission said it has suspended preparations for the vote. A further complication arose Tuesday when Kurdish leaders threatened to boycott the election unless the three northern provinces they control are given more seats in the next, 223-seat parliament. Hashemi has sent part of the law back to parliament to be amended so that more seats will be allocated for Iraqis living abroad, most of whom are Sunni Arabs. Hashemi said all other provisions in the law are satisfactory, and stressed that only the part related to the number of seats for voters abroad will be open for discussion. "My objection is not to the entire law, but only the first article in order to be fair to Iraqis living abroad," Hashemi told reporters. "I hope that parliament will hold a vote soon on the suggested amendments so that elections can be carried out at their schedule date." As one of three members of Iraq's presidential council, Hashemi holds veto power over legislation. It was not immediately clear when parliament would take up the vice president's suggestions, or what precise impact it would have on the date of elections. No final date has been set yet for the vote, but the constitution mandates that it be held before the end of January. Qassim al-Aboudi, a member of Iraq's electoral commission, said Hashemi's move will likely push back the election date and that the commission has suspended its preparations for the vote. "The situation is very difficult, and it is clear now that this will affect the commission's procedures and for sure will push the elections back," Aboudi said. A member of the parliamentary legal committee, Kurdish lawmaker Khalid Shwani, said the committee will study Hashemi's suggested changes as soon as they receive them. "If we received it today, then we will study the suggestions starting tomorrow and then we will put the article to a vote," Shwani told The Associated Press. "I can't put a specific timetable on the vote because it will depend on how long the discussions take." Prime Minister Nouri al-Maliki slammed al-Hashemi's decision to veto the bill, calling it "a serious threat to the political process and democracy." "It has no solid constitutional basis," a statement on the premier's Web site said. "The high national interests were not taken into consideration," said the prime minister, who has been locked in a bitter rivalry with Hashemi since Maliki took office in May 2006. Maliki also urged parties to forge ahead with their election preparations. Dominant for decades under Saddam, Iraq's minority Sunni Arabs have felt politically marginalized since the former dictator's ouster in 2003. They boycotted the first post-Saddam national elections in January 2005, and Hashemi's demands appear to stem from Sunni fears of being sidelined once again. Lawmakers haggled for weeks over the election legislation before finally passing it on Nov. 8, much to the relief of Iraqi political leaders and the United States, which pushed hard for a deal. Little more than a week later, the hard-fought agreement appears to be crumbling. Iraq's Kurds have also demanded changes to the law to ensure more seats for Kurdish regions in parliament, and on Tuesday threatened to boycott the elections unless their demands were met. That ultimatum, coupled with Hashemi's move on Wednesday, could undermine Iraq's fledgling democracy and trigger a constitutional crisis if the vote is not held by the end of January. The top US commander in Iraq said Wednesday that Washington's plans to withdraw all combat troops by the end of August 2010 remain on track despite the dispute over the election law. US commanders have tied the withdrawal to the national vote. Gen. Raymond Odierno told a news conference that the military can adjust its plans if the need arises, but that no decision has to be made before late spring. "We're set up and we're flexible enough between now and the first of May," he said. US military officials have said they will begin to draw down forces about 60 days after the election, hoping for assurances by then that Iraq is on stable footing. Under a plan by US President Barack Obama, all US combat personnel must be out of Iraq by the end of August 2010. The rest of the troops, such as trainers and support personnel, must leave by the end of 2011.