Roland Burris' quest for a U.S. Senate seat is expected to continue Monday with a meeting between his attorney and congressional leaders over the latest twists in the saga.
Fresh documents could bolster the legitimacy of his appointment by the scandal-plagued Gov. Rod Blagojevich, who was impeached Friday. Burris' attorney, Tim Wright, is looking to leverage a document signed by Secretary of State Jesse White certifying that Blagojevich's appointment had been filed by White's office.
Democratic leaders on Capitol Hill have been waiting for White's signature on Blagojevich's appointment before seating Burris. But White has refused to sign the certification paperwork, citing Blagojevich's problems with the law.
White, instead, filed a different document, showing that he had registered the arrival of the appointment. That development has given hope to Burris' side.
"We have the signature of Jesse White naming Roland Burris as senator from the state of Illinois," Wright told reporters. "We believe this matter will now move forward."
But Nathan Maddox, senior legal adviser to White, said White's letter registering Blagojevich's message "is not the official Senate appointment document."
On Capitol Hill, senior Democrats said they wanted to wait and see before offering any opinion on what the new document from White's office means.
"The Senate parliamentarian, the secretary of the Senate and the Senate legal counsel are advising Senate leadership as we consider a way forward," said Jim Manley, a spokesman for Senate Democratic Leader Harry Reid of Nevada.
An unnamed Burris adviser told Politico Saturday that if his appointment is not accepted, he will file a lawsuit against Reid and other Senate leaders.
"Unlike last time, there's now a sense that we've been forced into a corner and must be more direct with Senate leaders," the adviser told Politico.
"They're breaking the law and act as if they have the upper hand and can dictate terms for an entire state. There is nothing left to negotiate; they must seat the legally appointed senator."
The Illinois Supreme Court on Friday said in an unanimous opinion from all four Democratic and three Republican justices that White didn't need to sign the certification papers for Burris' appointment to become official. The court said Democratic leaders could go ahead and swear in Burris as a senator without it.
The squabble over the Senate appointment has been raging for two weeks now with Republicans hoping for a special election at which they might just grab a seat in the Senate. They hope to benefit from the scandal over Blagojevich and his alleged efforts to sell or trade the seat for a Cabinet position, a high paying job for himself or his wife or money to bankroll his future campaigns.
Democratic leaders appeared this week to be softening objections to seating Burris, although Burris has lost a string of statewide elections and hasn't won anything since the early 1990s -- something that may be on Democrats' minds as they look ahead.
Illinois Sen. Dick Durbin, the second ranking Democrat in the Senate said Burris cannot be seated without a missing signature certifying his appointment.
"There has never in the history of the Senate been a waiver of the requirement that the secretary of state's signature be part of the appointment process -- never," he said.
Durbin said efforts to fill the Senate seat vacated by Obama's election should go on hold until after the Senate holds an impeachment trial.
If Blagojevich is removed as governor, Lt. Gov. Pat Quinn will take over and can address the problem then "in a clean, legal and respectable way," Durbin said.
Despite the high court's ruling that no further action by state officials was necessary,
Durbin said what might be good enough for the court was not good enough for the Senate and that without White's signature, efforts to seat Burris should stop.
"I think it's best to suspend activities in the filling of that vacancy until that impeachment trial in the Illinois Senate is concluded," Durbin said. He said that if, as many lawmakers expect, Blagojevich is ousted, Quinn would have a free hand.
"I think that's the best way to turn the page," Durbin said.
FOX News' Ruth Ravve and The Associated Press contributed to this report.