BRASILIA, Aug 20 (Reuters) - Brazilian federal prosecutors presented formal charges against the speaker of the lower house of Congress, Eduardo Cunha, on Thursday in a widening political kickback scandal linked to contracts with state-run oil company Petrobras, the prosecutor's office said.
Cunha, the first sitting politician charged in Brazil's largest-ever corruption scandal, was accused of taking a $5 million bribe on two drillship contracts.
A member of Brazil's largest party, known as the PMDB, Cunha quit President Dilma Rousseff's coalition last month to join opposition lawmakers seeking her impeachment. The corruption charges will weaken Cunha's offensive against the president. (Reporting by Maria Carolina Marcello; Writing by Anthony Boadle and Caroline Stauffer; Editing by Peter Galloway)