Iraqis are voting in the first parliamentary elections since mass protests over corruption, unemployment and poor services erupted in 2019.
The old electoral system based on party lists has also been replaced with one meant to help independent candidates, reports BBC.
However, the main Shia Muslim blocs are still predicted to win the most seats.
They have dominated parliament since the US-led invasion in 2003, which overthrew Saddam Hussein's regime and ushered in a power-sharing system based on sectarian and ethnic identity that allowed a narrow elite to keep a firm grip on power and encouraged patronage and corruption.
The 2019 protests saw hundreds of thousands of mostly young people take to the streets of the capital, Baghdad, and cities in the predominantly Shia south to express their anger at the poor economic and living conditions endured by most Iraqis despite the country's enormous oil resources.
Then-Prime Minister Adel Abdul Mahdi's government resigned within weeks, but the protesters kept going and insisted that they wanted to sweep away the entire political establishment.