Updated

Iraq is holding its third parliamentary elections since the U.S.-led invasion that toppled dictator Saddam Hussein. Wednesday's vote is also the first after the withdrawal of the U.S. forces in 2011. More than 22 million voters are eligible to cast their ballots to choose 328 lawmakers out of more than 9,000 candidates.

Here's a look at the major political player and lists in the race to parliament:

STATE OF LAW: The main Shiite Islamist list that is led by Prime Minister Nouri al-Maliki. His main ally is Shiite deputy prime minister for energy, Hussain al-Shahristani, and also Hadi al-Amiri, a former commander of the Shiite Badr Brigades who now serves as transport minister. The list is expected to gain the largest number of seats, given its emergence as the largest single bloc in seven of 12 provinces in last year provincial elections. It came second in 2010 national elections after a Sunni-backed list.

AL-MUWATIN: One of the main rivals to State of Law, the bloc is headed by powerful cleric Ammar al-Hakim of the Shiite Supreme Islamic Iraqi Council. Some of the top candidates are the former interior and finance minister, Bayan Jabr, and Ahmed Chalabi, a prominent Shiite politician whose faulty intelligence was used by Washington to help justify the U.S.-led invasion. The bloc also includes former oil minister, Ibrahim Bahar al-Uloum.

AL-AHRAR: The bloc is made up of candidates from among the followers of firebrand Shiite cleric Muqtada al-Sadr. Few other Sadrists are fielding two separate small tickets. It is not expected to gain a significant number of seats, given al-Sadr's decision in February not to personally endorse any of his candidates.

AL-WATANIYA: A bloc under the leadership of former Prime Minister Ayad Allawi. In the 2010 parliamentary elections, Allawi's Iraqiya — which included the main Sunni parties and enjoyed the Sunni community's support — won the most seats. But Shiite parties joined forces and formed the largest political bloc in parliament, setting the stage for Allawi to be outmaneuvered and al-Maliki to be chosen for a second term.

MUTAHIDOUN: Led by Sunni parliament speaker, Osama al-Nujaifi, the bloc includes some prominent Sunni politicians in western and northern Sunni-dominated areas.

AL-ARABIYA: A bloc led by Sunni Deputy Prime Minister Saleh al-Mutlaq. Along with Mutahidoun, al-Mutlaq's bloc had defected from Iraqiya.

THE UNITED KURDISH ALLIANCE: The bloc is made of the two major Kurdish parties, the Patriotic Union of Kurdistan that is led by Iraq's president, Jalal Talabani, and the Kurdistan Democratic Party, which is under the leadership of the president of the self-ruled northern Kurdish region, Masoud Barzani.