CHICAGO — U.S. Sen. Dick Durbin said Friday that Roland Burris should not be seated in the U.S. Senate because he has failed to get the secretary of state's signature on his appointment to replace President-elect Barack Obama in the chamber.

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, Durbin, the Senate's second-ranking Democrat, told a news conference.

Durbin's statements came hours after the Illinois Supreme Court ruled that no law requires Secretary of State Jesse White to sign the appointment, made by Gov. Rod Blagojevich, to make it official.

White has steadfastly refused to sign because federal corruption charges against Blagojevich include allegations he tried to sell or trade the seat for personal or political favors.