Grand Ayatollah Ali al-Sistani says the next government should be made up of candidates who care about "the country's future and its citizens."
The cleric's remarks were relayed by his representative, Abdul-Mahdi al-Karbalaie, during Friday prayers in the Shiite holy city of Karbala.
The premier-designate, Haider al-Abadi, has until Sept 10 to submit a list of Cabinet members to parliament for approval but deadlines have often been broken because of political wrangling in Iraq.