The governor told journalists on Friday he was not surprised by the move and that it was because his colleagues disagreed with his moves to improve health care and cut property taxes for Illinois residents.

Since the scandal erupted he has denied all charges, refused to resign, and recently appointed his own replacement for Obama's seat, Roland Burris, a former Illinois attorney general.

Senate leaders at first rejected Burris, however under pressure from Obama later said they would seat him.

'Freak show' claims

"It's our duty to clean up the mess and stop the freak show that's become Illinois government"

Jack Franks, member of Illinois house of representatives

On Friday, legislators at the impeachment proceedings accused the governor of letting down the people of Illinois in a scandal that has embarrassed the Democratic party ahead of Obama's inauguration on January 20.

"It's our duty to clean up the mess and stop the freak show that's become Illinois government,'' said Jack Franks, a representative in the house.

Obama and several of his aides were questioned by federal investigators about their contacts with Blagojevich regarding his seat, however an internal review found his team had no "inappropriate" contacts with the Illinois governor's office.

The last US governor to be impeached was Evan Mecham, Republican governor for Arizona, in 1988.

Corruption claims

Among the allegations against the governor are several corruption accusations contained in a 76-page FBI affidavit.

In one case, Blagojevich is alleged to have refused to free up funds for a children's hospital until he received a $50,000 campaign contribution.

He is also accused of trying to get editors who were critical of his administration fired from the Chicago Tribune newspaper.

Blagojevich's lawyers meanwhile have dismissed partial transcripts of taped conversations about how the governor could trade Obama's vacated US senate seat for a cabinet post, ambassadorship or high-paying job.