The ex-paramilitary group challenged the October 10 parliamentary election results, in which it lost 33 seats.
By law, Judge Jassem Mohamed Aboud, in charge of the case, must rule before next Parliament is formed.
The Sairoon Alliance, led by Shiite Muslim cleric Moqtada al-Sadr, was declared on November 30 the winner of the elections, with 73 out of 329 seats in dispute, far behind those won by the Fatah (Conquest) Alliance.
The leaders of al-Hashd al-Shaabi allege that there was manipulation in the elections, after only adding 15 out of 48 seats it held.
After the final ruling on the elections, the Parliament will hold its opening session and will elect a speaker, who in turn, will appoint a prime minister who requires the legislators’ approval.