BAGHDAD - Billed as a key test of Iraq's nascent democracy, Iraqis fear today's parliamentary election will lead to a protracted period of uncertainty as the winners and losers try to cobble together a new government - even as American forces prepare to go home.

None of the main political coalitions is expected to win an outright majority, which could mean months of negotiations and more violence despite hopes the balloting will boost efforts to reconcile Iraq's divided ethnic and religious groups.

Iraq's second nationwide election for a full parliamentary term comes at a vastly different time than the first in December 2005.

The U.S., which has lost more than 4,300 troops in the nearly seven-year conflict, has fewer than 100,000 troops in the country and their presence on the streets has all but vanished. The monthly American death toll has plummeted.

Overall violence is down dramatically, although attacks continue and insurgents have threatened voters.

A car bomb targeted Iraqi and Iranian pilgrims in the Shiite holy city of Najaf on Saturday, killing at least three people, including two Iranians, and wounding more than 50, officials said.

The balloting for a new 325-seat legislature has been billed as a major step in Iraq's democratic evolution. Iraqis hope it will help them achieve national reconciliation at a time when the United States has vowed to stick to President Barack Obama's timetable that calls for the withdrawal of combat forces by late summer and all American troops by the end of next year.

But many observers have predicted it could take months for rival factions to form a new government. The bloc with the most votes will be able to nominate a prime minister but is probably going to need support from others to gain a majority due to the fractured nature of Iraqi politics.

Prime Minister Nouri al-Maliki's government will stay in place until the new government is formed but on the practical side, not a lot of work may get done as ministers who are worried about retaining their jobs or scrambling for new ones lose focus on the day-to-day running of the government.

The instability also would leave the door open for more violence as political groups that don't get what they want at the negotiating table take to the streets.

"This is a cause of considerable concern because there would be a kind of a vacuum," said Adnan Pachachi, the elder statesman of Iraqi politics who is also running for parliament. "It is in everyone's interest to try to form a government very soon."

The vibrant political campaigning has seen large-scale rallies, town-hall style meetings and campaign posters and television ads that blanket the city and the airwaves, reflecting the high stakes involved. More than 6,200 candidates are vying for a seat.

Al-Maliki heads the State of Law Coalition, a largely Shiite group that presents itself as nonsectarian but is dominated by the religious Dawa party. Al-Maliki has risen to popularity as violence has diminished but his image has been tarnished by the government's inability to stop large-scale bombings in Baghdad or provide basic services like electricity.

The U.S.-backed leader also faces intense pressure from his former Shiite allies - the Supreme Iraqi Islamic Council and the Sadrist Trend led by anti-American cleric Muqtada al-Sadr - who are closely allied with Iran and have teamed up in a separate alliance.

In a surprise move ahead of the election, al-Sadr made a rare public appearance Saturday in neighboring Iran, where he's believed to have been living for the past two years, studying at Iran's foremost seat of Shiite learning, Qom.

Speaking from Tehran, al-Sadr - flanked by two Iraqi flags - urged Iraqis to turn out in large numbers Sunday and give their support to those who he said were "faithful" to the Iraqi people.

The appeal marked a significant shift in al-Sadr's position on Iraqi elections. He has viewed past votes as illegitimate because they took place under the canopy of U.S. occupation. But in the run-up to this election, the cleric called voting a means of "political resistance," a new stance that could boost Sadrist turnout and representation in the next government.

The Iraqiya list, led by former Prime Minister Ayad Allawi, a secular Shiite, has attracted both Shiites and Sunnis for its secular stance and its high-profile Sunni candidates.

Sectarianism is still the dominant force in Iraqi politics. A Shiite-led ban that knocked out hundreds of candidates angered Sunnis. The leader of the ban - former Pentagon favorite Ahmed Chalabi - is a candidate himself and proudly describes himself as "the destroyer of Baath idols" in his campaign posters.

But there are signs - albeit small - that Iraqis are thinking beyond the strictly sectarian lines that have defined them. The major coalitions have paid at least lip service to including members of other Muslim faiths, a contrast to the 2005 vote.

"What you had basically was Kurds voting for Kurds, Sunnis voting for Sunnis and Shiites voting for Shiites," said former U.S. ambassador to Iraq, Zalmay Khalilzad. "This time, it looks like people are moving away, not totally of course, but incrementally away from sectarianism."

The Kurdish Alliance, made up of the main Kurdish political parties who dominate in their self-rule northern region, won't form the government in this Shiite-majority country, but their political unity means they will likely help decide who does. Key to their negotiations will be the future of Kirkuk, the oil-rich city that is claimed by both Arabs and Kurds.

But even the Kurds are divided with a new party called "Change" eating into the two traditional Kurdish parties' lock on power.

Kenneth Pollack, an analyst with the Saban Center at the Brookings Institution, said one outcome of the election could be that the main factions end up with roughly the same number of seats.

"It could just be a recipe for a protracted struggle," said Pollack. "All the militia leaders and the thugs are going to start getting very impatient."

In the roughly five months it took to form a government after the December 2005 ballot, the insurgency took off and the Feb. 22, 2006, bombing of a golden domed Shiite mosque north of Baghdad, blamed on Sunni insurgents, set off months of sectarian bloodletting.

Nobody is predicting a return to the violence seen in 2006 and 2007. Iraqis are exhausted from the violence, and government security forces have their weaknesses but are vastly improved.

U.S. forces will be providing surveillance, reconnaissance and intelligence for the vote, but Iraqi forces will be in the lead, said Lt. Gen. Charles Jacoby, the No. 2 U.S. commander in Iraq.

Much will hinge on how legitimate Iraqis feel the elections are. The United Nations mission in Iraq has said sophisticated anti-fraud measures are in place to oversee the vote, including specially imported purple ink from China used to mark voters' fingers to prevent them from voting twice.

But complaints during an early round of voting on Thursday of people not being able to find their names on the voting lists illustrate the skepticism with which many Iraqis view the political system.