The top prosecutor for the state of Illinois says she may take action to force Governor Rod Blagojevich from office, following his arrest on corruption charges.
State Attorney General Lisa Madigan says she is prepared to go to the Illinois Supreme Court to have the governor, a fellow Democrat, declared unfit to serve.
Federal prosecutors accuse Blagojevich of seeking bribes and favors in exchange for naming a particular candidate to the U.S. Senate seat vacated by President-elect Barack Obama.
Mr. Obama Thursday said he is certain that his office was not involved in any dealmaking, and repeated his call for the governor to resign.
Lawmakers in Illinois and Democrats in the U.S. Senate also have urged him to step down, but he has ignored those calls. He returned to work Wednesday, a day after his arrest.
Illinois lawmakers are expected to meet Monday to discuss ways to strip Blagojevich of his power to name Mr. Obama's replacement in the Senate. They will seek to hold a special election for the seat instead.
Prosecutors allege other instances of abuse of power by Blagojevich. They say he threatened to withhold state aid to a newspaper company, the Tribune Company, unless editorial staff members critical of him were fired. They say he also threatened to withdraw funding from a children's hospital unless he received $50,000 from an executive.
Mr. Obama, who resigned from his Illinois U.S. Senate seat shortly after winning the November 4 presidential election, says he had no contact with the governor or his office about the Senate seat.