Burris, 71, arrived on Capitol Hill in a bid to take the seat vacated by President-elect Barack Obama but was turned away.

"I presented my credentials to the secretary of the Senate and was advised I would not be accepted, I would not be seated, I would not be allowed on the senate floor," Burris told reporters afterward.

The Senate leadership is using Illinois Secretary of State Jesse White's refusal to certify Burris's appointment as the basis for rejecting him.

"I will now consult my attorneys and we will determine what my next step will be," Burris pledged.

Burris, who came out of political retirement to claim the Senate seat, told reporters on the steps of the Capitol he was looking at a host of options.

Burris attorney Timothy Wright III called the Senate action "improper."

"It is against the law of the land," Wright said.

The appointment is controversial because Illinois Gov. Rod Blagojevich is under investigation for allegedly trying to sell Obama's seat to the higher bidder, among other allegations. Senate Majority Leader Harry Reid, D-Nev., said no one appointed by Blagojevich would be acceptable to the body.

Earlier in the day, Burris said in an interview on the CBS "Early Show," White's refusal to certify him isn't fair since White certified Blagojevich's decision to call a special election to fill the U.S. House seat vacated by Obama Chief of Staff-designate Rahm Emanuel.

Meanwhile, a state House panel determining whether to impeach Blagojevich subpoenaed Burris to appear before it Wednesday. During a news conference at Chicago's Midway Airport before he left for Washington, Burris said he had scheduled a meeting with congressional leaders for Wednesday and was trying to arrange to travel to the Illinois statehouse on another date, possibly Thursday, the Chicago Tribune reported.

Burris said he sent the panel an affidavit in response to their subpoena, sought by Republican members who said he needed to explain how he got the appointment.