Essawi's remarks may reignite a long-running feud between the secular, Sunni-backed Iraqiya bloc, of which he is a member, and the Shiite premier.

"I call on the prime minister to resign, because he did not behave like a man of state," Essawi told a news conference attended by parliament speaker Osama al-Nujaifi and Deputy Prime Minister Saleh al-Mutlak, both of whom are also Iraqiya members.

Essawi said a "militia force" -- an apparent reference to a security forces unit -- raided the finance ministry and his home "in an illegal act, without a judicial order," detaining all of the ministry's 150 guards.

Iraqiya and other members of Maliki's less-than-unified national unity government have accused him in the past year of concentrating power in his hands and moving towards dictatorship.

Opposition to Maliki escalated into calls for him to be removed from power, but his opponents lacked the parliamentary votes to do so. Essawi also called on Thursday for the no-confidence proceedings to be reopened.