Lisa Madigan took the action as pressure on the governor intensified to step down. Madigan scheduled a news conference in Chicago Friday morning to discuss the motion.
The move came as the governor prayed with several ministers in his home before heading to his office, telling them he is innocent and will be vindicated "when you hear each chapter completely written," according to one of the pastors.
The attorney general asked the court for a temporary restraining order or an injunction that prevents Blagojevich from serving as governor. The filing says he is "unable to serve as governor due to disability and should not rightfully continue to hold that office."
"The pervasive nature and severity of these pending charges disable Mr. Blagojevich from making effective decisions on critical, time-sensitive issues," the filing said.
The filing asks that the lieutenant governor assume Blagojevich's powers.
It is the first time in Illinois history that such an action was taken. The attorney general is applying a rule that was intended to cover cases where a governor is incapacitated for health reasons. Her motion indicates that his inability to serve because of the scandal is akin to a debilitating health issue.
The motion essentially declares that Blagojevich's legal problems amount to a disability that would not be resolved until he is either cleared of the charges or leaves office.
"Mr. Blagojevich is unable to distinguish between his financial interests and his official duties and between illegal acts and legal conduct, rendering him incapable of legitimately exercising his ability as governor," Madigan says in the motion.
"His ability to provide effective leadership has been eliminated and the state government is paralyzed."
The motion came three days after Blagojevich was accused of putting Barack Obama's Senate seat up for sale and shaking down the owners of the Chicago Tribune.
The governor has been alternately holed up in his home or his downtown office since his arrest on federal corruption charges. He met with clergymen Friday morning.
The Rev. Ira Acree of the Greater St. John Bible Church said Blagojevich would not discuss details of the allegations against him.
He said the governor discussed trying to get a legal and political consultation team in place, but feels as if everything is closing in on him and that he's not getting "any space or chance to sort anything out."
Acree and two other pastors -- The Rev. Steve Jones, president of the Baptist Pastor's Conference, and the Rev. Marshall Hatch of the New Mt. Pilgrim Missionary Baptist Church -- arrived at the governor's home shortly after 8 a.m. and met with him for about 20 minutes.
Jones said they prayed with Blagojevich and his family.
"I look at it like this: Everybody that's hurting needs hope and the family needs hope and that's what our jobs are as pastors," Jones said. "Nobody should be left hopeless. Nobody, no matter what the circumstances."
Shortly after they left, a fourth minister, the Rev. Leonard Barr of Fellowship Missionary Baptist Church, arrived at the governor's house with his wife, Rita.
He said they were invited by the governor and that the two "prayed that he would continue to be a great governor for the state of Illinois."
Meanwhile, calls for the governor to step down are intensifying. The lieutenant governor has joined a bevy of lawmakers in demanding that Blagojevich be impeached, saying he has become an embarrassment to the state and can no longer lead. His approval rating plummeted to a shockingly low 8 percent.
"When you have no confidence from the people, in a democracy there's nowhere else to go but to resign," Lt. Pat Quinn said Thursday.