Leading Democrats have called for a special election to fill the Senate seat left vacant by Barack Obama after Rod Blagojevich, the Governor of Illinois, was charged with trying to sell it to the highest bidder yesterday.

Calls for a poll – removing the Governor's right to appoint a replacement – came after Mr Blagojevich 's arrest, exposing further the endemic corruption in the President-elect's home state.

Analysts said an emergency election could open the door to a Republican being elected to the seat.

In a 76-page affidavit issued yesterday, the FBI outlined what it said was an extraordinary attempt by Mr Blagojevich to extract a price for exercising his power to appoint a Senator to fill Mr Obama’s vacated seat.

In a secretly recorded conversation, he allegedly said that the Senate seat “is a f***ing valuable thing, you just don’t give it away for nothing”.

Also included in the allegations were claims that the Democratic governor, who has served two-terms, conspired with Antoin “Tony” Rezko – a political donor for Mr Obama and a former friend – in schemes requiring individuals and companies to pay kickbacks in return for state contracts.

The scandal leaves the Senate seat in limbo, and Democrats both nationally and locally have said a special election should be held to fill Mr Obama’s seat.

“No appointment by this governor, under these circumstances, could produce a credible replacement,” said Dick Durbin, the remaining Illinois Democratic Senator and assistant majority leader, said.

Harry Reid, the Democratic Senate majority leader, added: “It is clear that anyone Governor Blagojevich appoints to the senate will fairly or unfairly be tainted by questions of impropriety.

"A different process to select a new senator must be put in place – and that process should not involve Governor Blagojevich."

Holding a special election would require a new law being passed by the state Senate. Reports suggested an emergency session was being prepared.

The scandal could give the Republicans a shot at winning what would usually be a safe seat and giving the party a vital boost in the Senate. “With this so fresh in the minds of voters, Republicans may have a chance at this seat in a special election,” one Democratic operative from Illinois was quoted as saying on Politico.com.

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