Washington  - The US Senate has refused to seat Roland Burris, the candidate selected by embattled Illinois Governor Rod Blagojevich to fill president-elect Barack Obama's Senate seat.

The secretary of the Senate rejected Burris' credentials because they had not been properly certified by Illinois officials, and would not allow him to take the oath of office as Congress opened its new session on Tuesday.

Senate leaders had vowed to block Blagojevich's appointment of Burris, 71, because of the ongoing investigation of the governor, who was arrested December 9 on corruption charges.

Federal authorities accuse Blagojevich of attempting to solicit bribes or political favours from potential candidates to replace Obama, among other charges.

Burris departed the Senate and announced that he was not allowed to take his seat. He told reporters he would consult with his lawyers before proceeding.

Burris, a Democrat, has not been implicated for any wrongdoing, but Senate Majority Leader Harry Reid, also a Democrat, believes any Blagojevich appointment would not be credible.

Top Democrats, including Obama, have called for the Illinois state legislature to make the appointment or hold a special election.

Burris' credentials required two signatures: Blagojevich's and Illinois Secretary of State Jesse White's. But White refused to sign the document.

Burris has maintained that his selection was legal under the US and Illinois constitutions, and that he should be permitted to join the Senate. He defiantly told reporters on Monday that he considered himself the senator from Illinois and intended to show up for the job.

Blagojevich faces up to 20 years in prison if convicted on the broad corruption charges. (dpa)