Illinois’ lieutenant governor called Thursday for lawmakers to quickly address the “urgent matter” of impeaching embattled Gov. Rod Blagojevich, who has given no sign of plans to heed calls for his resignation.

“Illinois is in crisis,” Lt. Gov. Patrick Quinn said Thursday at the state Capitol.

Blagojevich went to work in his Chicago office without commenting. “He’s working,” said spokeswoman Kelley Quinn.

Blagojevich was arrested Tuesday on charges he put President-elect Barack Obama’s Senate seat up for sale.

Obama, meanwhile, told a news conference that neither he nor members of his staff were involved in making a deal with the disgraced governor. He called on Blagojevich to resign.

Illinois Attorney General Lisa Madigan again threatened to go to the state Supreme Court to have Blagojevich declared unfit to hold office if he doesn’t resign soon or get impeached.

“I have the opportunity to go to our Illinois Supreme Court and ask them to declare our governor is unable to serve and put in our lieutenant governor as acting governor,” Madigan, a longtime Blagojevich foe who is considering a run for governor in 2010, told CNN.

She said she “won’t wait terribly long” but wants a signal from lawmakers if they will move quickly on impeachment proceedings.

Legislative leaders planned a special session Monday to strip Blagojevich of his power to pick a new U.S. senator, putting the decision in the hands of Illinois voters instead. Lawmakers also prepared to discuss the possibility of impeachment.

Quinn said the impeachment process should begin when the Legislature convenes and if lawmakers don’t take action, he would support Madigan going to the Supreme Court.

“The Legislature should focus on the source of the problem,” Quinn said. “The governor is in office and he needs to be removed from office. … I think that is what the people of Illinois want.”

Quinn strongly criticized setting up a special election to fill Obama’s vacant Senate seat. He said it would cost millions of dollars and take months, leaving Illinois with just one senator in Washington.

He said it would be better if Blagojevich were removed so Quinn becomes governor and can name a senator.

Quinn said he hasn’t spoken to potential Senate appointees and doesn’t have a short list of candidates for the job. He said if anyone contacted him to discuss an appointment, he would tell them it was premature.

Blagojevich’s lawyers have insisted he is innocent, and stressed that he still has important work to do for the state of Illinois.

The White House on Thursday said President George W. Bush finds Blagojevich’s alleged behavior “astounding.”

Blagojevich’s decision to show up for work Wednesday like it was another day at the office angered much of the state’s political establishment, and Obama and U.S. Senate leaders demanded that he step down. The prospect that the second-term Democratic governor might still try to appoint someone to the Senate also loomed.

“He appears to listen to no one, and his conduct becomes more outrageous as time goes on,” said Steve Brown, spokesman for Illinois House Speaker Michael Madigan.

The first fallout from the scandal also emerged Wednesday, with U.S. Rep. Jesse Jackson Jr. denying any misconduct while confirming that he is the Senate candidate mentioned in the federal charges as someone Blagojevich thought would pay money to be appointed to the seat. Jackson, the son of the Rev. Jesse Jackson, said he had been assured by prosecutors he was not a target of the investigation.

On Tuesday, FBI agents arrested Blagojevich at his home and took him away in handcuffs. Prosecutors released a thick document that included excerpts of wiretapped conversations in which the governor allegedly schemed to enrich himself by offering to sell Obama’s Senate seat for campaign cash or a lucrative job inside or outside government.

They also alleged he pressured the Tribune Co. to fire editorial writers at the Chicago Tribune after several negative editorials about Blagojevich.

Blagojevich is charged with conspiracy and solicitation to commit bribery, punishable by up to 20 years in prison and 10 years, respectively.

More than 24 hours after the arrest, Obama joined other prominent Democrats in calling for Blagojevich’s resignation.

“The president-elect agrees with Lt. Gov. Quinn and many others that under the current circumstances it is difficult for the governor to effectively do his job and serve the people of Illinois,” Obama spokesman Robert Gibbs said.

Asked whether Obama supports a special election, Gibbs said Obama believes the Illinois General Assembly should consider how to fill the Senate seat and “put in place a process to select a new senator that will have the trust and confidence of the people of Illinois.”

Senate Democrats were more pointed in a letter to the governor: They “insist that you step down” and not name anyone to replace Obama. An appointment by a new governor would “be the most expeditious way for a new senator to be chosen and seated in a manner that would earn the confidence of the people of Illinois and all Americans,” wrote Majority Leader Harry Reid of Nevada and the party’s second-ranking leader, Sen. Richard Durbin of Illinois.

They suggested the Senate might reject anyone chosen by Blagojevich. The Constitution gives the Senate authority to refuse to allow a member to be sworn in.

It was unclear what incentive the governor had to give up his office.

A resignation might make him appear guilty. The office also gives him a certain amount of clout, which can help him raise money for his defense.

Republican Sen. Christine Radogno said it’s possible Blagojevich would use his resignation as a bargaining chip with prosecutors and agree to step down in exchange for leniency.

When Illinois lawmakers meet Monday, they’ll consider changing state election law to fill Senate vacancies by special election, rather than leaving the decision to the governor. But holding an election could take months and give Republicans a shot at capturing a seat now in Democratic hands.

Brown, the spokesman for the House speaker, noted that any change in the law would go to the governor’s desk, where Blagojevich could let it sit and still pick a senator.

“Despite our best efforts, the governor could play hide the ball. That is an inescapable reality,” Brown said. “I’m hoping that’s not the case.”

Brown said the speaker hasn’t ordered staff to begin researching impeachment but that individual legislators are doing so. The speaker’s office also compiled a memo earlier this year on arguments for impeaching the governor.