Jackson said this morning he was contacted Tuesday by federal prosecutors in Chicago whom he said "asked me to come in and share with them my insights and thoughts about the selection process."
Jackson Jr.'s attorney James Montgomery confirmed today that the Chicago congressman is "Senate Candidate #5" but said "Jackson has never authorized anyone to seek the Governor's support in return of money, fundraising or other things of value."
Jackson said "I don't know" when asked if he was Candidate #5 earlier this morning, but said he was told "I am not a target of this investigation."
Jackson he agreed to talk with federal investigators "as quickly as possible" after consulting with a lawyer. Montgomery said his client would meet with prosecutors Friday or Monday.
The congressman, a son of the famed civil rights leader, denied that anyone had been authorized to make payments or promises to the governor on his behalf.
"It is impossible for someone on my behalf to have a conversation that would suggest any type of quid pro quo or any payments or offers," Jackson told ABC News. "An impossibility to an absolute certainty."
"Senate Candidate No. 5" played a key role in the governor's efforts to obtain something of value in exchange for the Senate appointment, according to the FBI affidavit.
According to the affidavit, Blagojevich threatened to appoint Senate Candidate No. 5 if President-elect Obama refused to help get his wife on "paid corporate boards right now."
"If they feel like they can do this and not f-- give me anything then I'll f-- go [Senate Candidate 5]."
The FBI says that during an Oct. 31 conversation, Blagojevich described an approach from an associate of Senate Candidate 5: "We were approached 'pay to play.' That, you know, he'd raise me 500 grand. An emissary came. Then the other guy would raise a million, if I made him [Senate Candidate 5] a senator."
On Thursday, the FBI says Blagojevich "was giving Senate Candidate 5 greater consideration for the Senate seat" because he might "get some [money] up front, maybe."
Blagojevich is back to business as usual working in his Chicago office today, which is his 52nd birthday. "The day-to-day operation doesn't change nor is it affected. There are still critical state issues that he wants to address -- things like dealing with the current financial crisis, looking at ways to keep people in their homes and finding ways to create jobs -- and will continue to do so as governor," said a spokesperson. Meanwhile, Obama and Senator Dick Durbin (D-IL) are now calling for the governor's resignation.
Meanwhile, a top aide to Blagojevich, Illinois Deputy Governor Bob Greenlee, resigned today. The reason for his resignation wasn't immediately clear.
Blagojevich and Jackson Jr. Met Monday Afternoon
Blagojevich met with Jackson Monday afternoon and said he was close to making a decision about whom he would appoint.
The governor was arrested by the FBI early Tuesday morning in order to "stop a crime spree," according to U.S. Attorney Patrick Fitzgerald.
Jackson said Tuesday that he met with Blagojevich Monday "for the first time in years" and voiced his desire to fill Obama's empty Senate seat. He said he was "shocked" by Blagojevich's arrest, adding that "if these allegations are proved true, I am outraged by the appalling, pay-to-play schemes hatched at the highest levels of our state government."
Jackson is only one of a number of Illinois political figures whom the FBI is expected to interview in Chicago and Washington. But fellow Illinois Democratic Reps. Luis Gutierrez, Jan Schakowsky and Danny Davis, as well as Illinois Attorney General Lisa Madigan, all say they have not been contacted by the FBI or prosecutors in connection to the Blagojevich investigation.
Madigan has confirmed, however, that she is Senate Candidate #2 in the affidavit, but she denied having any conversations with Governor Blagojevich about the Senate seat.
According to the affidavit, Blagojevich wanted it leaked to the Chicago-Tribune that Senate candidate number 2 was running for the vacant seat because he wanted to "send a message to the [President-elect's] people." Madigan said that if Blagojevich does not resign and the legislature fails to impeach him, she is prepared to invoke Illinois law that could result in his removal from office. She said she may be prepared to take this step sooner rather than later if it appears the legislative impeachment process is too protracted, declaring "Illinois needs a new Governor."
In addition to the hours of wiretap tapes, which reveal only Blagojevich's version of events, agents are seeking firsthand accounts from anyone who dealt with Blagojevich over Obama's vacant Senate seat.
According to an FBI affidavit unsealed after the governor's stunning arrest Tuesday, Blagojevich wanted Obama "to put something together -- something big" in exchange for going along with Obama's choice to fill his vacant U.S. Senate seat.
"I've got this thing and it's f-- golden, and, uh, uh, I'm just not giving it up for f--' nothing. I'm not gonna do it. And I can always use it. I can parachute me there," Blagojevich said during a phone call secretly recorded by the FBI Nov. 5, the day after the election, according to the affidavit.
Fitzgerald said, "There's no reference in the complaint to any conversations involving the president-elect or indicating that the president-elect was aware of it, and that's all I can say." His comment did not close the door on the possibility that Obama or someone on his staff may have known of some aspect of the governor's demands.
There are strong indications that Candidate 1 may be Valerie Jarrett, Obama's close confidante who has since been named a special presidential adviser. Senate Candidate 1 is identified in the federal documents as an adviser to the president-elect.
Durbin said Blagojevich was considering Jarrett until she withdrew her name from consideration. "The governor asked me if I thought she [Jarrett] was serious about not being appointed and I said, 'yes, she told me point blank that she was,'" Durbin said.
The federal complaint also states that Candidate 1 eventually withdrew from consideration.
In addition, Durbin declined to speculate whether Senate Candidate 5 could be in peril.
The FBI says Blagojevich wanted an appointment to the Obama Cabinet as secretary of the Health and Human Services Department, a well-paying job, or huge campaign contributions as the price for naming Obama's successor.
Blagojevich Overheard by FBI Saying: 'I Want to Make Money' Blagojevich was overheard by the FBI saying "I want to make money" and complaining that he was "financially hurting."
Blagojevich also sought a high-paying job for his wife, according to the FBI. "Is there a play here, with these guys, with her" to work for a firm in Washington or New York, he reportedly asked.
The FBI affidavit said Blagojevich had been told by an adviser "the president-elect can get Rod Blagojevich's wife on paid corporate boards in exchange for naming the president-elect's pick to the Senate."
Told by two other advisers he has to "suck it up" for two years, the FBI says, Blagojevich was heard complaining that he has to give this "motherf-- [the president-elect] his senator. F-- him. For nothing? F-- him."
The affidavit said that Blagojevich was interested in a high-paying position with Change to Win, an organization affiliated with the Service Employees International Union (SEIU), and that he suggested in a conversation with a SEIU official on Nov. 12 that Obama wanted other people to be considered for the Senate seat besides Senate Candidate 1. Previous phone conversations indicated that Blagojevich knew the SEIU official "was an emissary to discuss Senate Candidate 1's interest in the Senate seat," the affidavit said.
"Harris suggested that SEIU Official make Rod Blagojevich the head of Change to Win and, in exchange, the President-elect could help Change to Win with its legislative agenda on a national level," noted the affidavit.
SEIU has denied any involvement, saying in a statement, "We have no reason to believe that SEIU or any SEIU official was involved in any wrongdoing."
Change to Win released a statement saying that the organization never "considered, discussed or promised" any position to Blagojevich or his staff and that the group only learned of conversations between the governor and his advisers discussing such a position upon the release of the affidavit today.
The FBI affidavit says Blagojevich thought he might get something "tangible up front" from Senate Candidate 5.
Aware that he was under FBI investigation, Blagojevich apparently considered appointing himself to Obama's Senate seat, the affidavit says. He is quoted as saying, "He will be able to obtain greater resources if he is indicted as a sitting senator as opposed to a sitting governor."
Emma Schwartz, Jake Tapper, and Andy Fies contributed to this report.