Washington - A committee of the Illinois State Legislature on Thursday backed impeachment for Governor Rod Blagojevich, who was accused last month of trying to sell president-elect Barack Obama's vacant US Senate seat to the highest bidder.

A special committee of the Illinois House of Representatives voted unanimously to send Blagojevich's impeachment to the full House.

Illinois House Speaker Mike Madigan, a fellow Democrat but longtime political rival of Blagojevich, predicted after the 21-0 that the lower chamber would quickly pass the impeachment of Blagojevich, sending his fate in office to a trial by the State Senate.

I think that the House will vote in favor of impeachment," Madigan said, the State Journal-Register, the daily newspaper in the capital Springfield, reported on its website late Thursday.

Blagojevich was arrested last month at his home in Chicago by federal authorities, who accused him of trying to sell an appointment to the US Senate left vacant by Obama's election to the presidency. Illinois law gives the governor the power to appoint a successor to a US Senate vacancy.

Federal court documents say that Blagojevich was recorded in wire- tapped telephone conversations repeatedly stating his intent to gain personal benefits, such as a high-paid labour union job, in exchange for granting the Senate post, calling it "golden."