Rod Blagojevich (file photo)

Efforts are moving quickly to oust defiant Illinois Governor Rod Blagojevich, who is accused of trying to sell the U.S. Senate seat left vacant by President-elect Barack Obama.

The speaker of the Illinois House of Representatives has told state lawmakers to be ready to vote on the governor's impeachment as early as next week.

Blagojevich has defied calls from leaders of his own Democratic Party to step down and last week named a veteran Illinois lawmaker, Ronald Burris, to fill Mr. Obama's Senate seat.

State officials have refused to certify the governor's appointment, and U.S. Senate leaders have said they will not accept anyone named by Blagojevich.

Settling the scandal is becoming increasingly urgent because U.S. senators are scheduled to convene in Washington for a new session on Tuesday.

Blagojevich was arrested in early December for allegedly trying to sell the U.S. Senate seat to the highest bidder.

Democratic leaders, including President-elect Obama, have said Blagojevich should resign because he can longer effectively lead the state.

Blagojevich denies wrongdoing and has vowed to fight the federal corruption charge against him.