The new law redraws each of the country's 18 provinces into several electoral districts, with one legislator elected per 100,000 people.

It also prevents parties from running on unified lists, which in the past have helped them easily sweep all the seats in a specific province. Instead, seats will go to whoever gets the most votes in the electoral districts.

Mass protests have gripped Iraq since October over official corruption and a lack of jobs, as well as frustration with the political system in place since the 2003 U.S.-led invasion.

More than 400 people have been killed in the unrest.

Protesters have demanded not just a new electoral law, but also the removal of the entire political class and an independent prime minister with no party affiliation.

Prime Minister Adel Abdul Mahdi resigned last month under pressure from the street demonstrations but has remained in office in a caretaker capacity.

The constitutional deadline to name a replacement expired late last week.

Based on reporting by AP and Reuters