Federal prosecutors on Jan. 3 charged the chairman of Chicago’s powerful finance committee with one count of extortion. Edward M. Burke has served on the city council for 50 years and has been chairman of the finance committee for 30. Burke was accused of asking for both work for his law firm, Klafter & Burke, and a campaign contribution for an ally, Cook County Board President Toni Preckwinkle, in exchange for expediting construction permits for a remodeling and driveway work of a Burger King restaurant in his South Side ward. Burke, 75, faces up to 20 years in prison. The indictment stated the investigation involved recorded calls on Burke’s cell phone and federal surveillance of the alderman. Preckwinkle, a declared Chicago mayoral candidate, said she will return $116,000 from a fundraising event at Burke’s home a year ago.