In what can be termed as a "crisis situation," Illinois lawmakers are scrambling to find a way to force the exit of Governor Rod Blagojevich, while President-elect Barack Obama has called for his resignation, and Senator Harry Reid, the majority leader, warned him that he should "under no circumstances make an appointment" to the US Senate seat vacated by Obama.

The two-term Democratic governor of Illinois was arrested at home before dawn on Tuesday and then released without having to post bail.

In a 76-page criminal complaint against Blagojevich on Tuesday, some of the elements sketched out came into sharp view, as federal authorities identified Representative Jesse L. Jackson Jr. of Illinois as the potential Senate candidate, who was described in the complaint as most intertwined with Blagojevich in deal-making for the vacant seat.

Obama called on the governor to resign on Wednesday. Obama called the charges against Blagojevich "sobering and sad", and added that he has had a cool relationship with the governor, who has been under investigation on other issues for years. There were mounting calls within Obama's home state to strip Blagojevich of the power to make the appointment he allegedly tried to barter, either by driving him from office through legal means or letting voters fill the Senate seat with a special election. Robert Gibbs, an Obama spokesman, said Gov. Rod Blagojevich needed to step down because "under the current circumstances it is difficult for the governor to effectively do his job and serve the people of Illinois."

The 50 members of the Senate Democratic Caucus also called on Blagojevich to step down and refrain from naming Obama's successor, and even threatened refusal to seat any replacement chosen by the Illinois governor.