The governor of Illinois was arrested yesterday on charges of conspiring to get financial benefits through his authority to appoint a US senator to fill the vacancy left by Barack Obama's election as president.

According to a federal criminal complaint, Governor Rod Blagojevich was also charged with illegally threatening to withhold state assistance to Tribune Co, the owner of the Chicago Tribune, in the sale of Wrigley Field. In return for state assistance, Blagojevich allegedly wanted members of the paper's editorial board who had been critical of him fired.

The FBI affidavit said Blagojevich was intercepted on court-authorized wiretaps over the last month, conspiring to sell or trade the vacant Senate seat for personal benefits for himself and his wife, Patti.