Guatemalan Catholic bishops have called for an overhaul to the country's electoral law and for political parties to wipe out corruption amid a widening crisis that has left President Otto Perez Molina fending off calls for his resignation. In a letter issued on Wednesday, the bishops' conference said it supported protesters who have held demonstrations across the country during the past month, demanding President Perez, a former military general elected in 2011, step down. "We need to break the cycle of corruption, impunity and conflict to be a different Guatemala," said the letter, signed by Bishop Rodolfo Valenzuela Nunez of Vera Paz, conference president, and Bishop Domingo Buezo Leiva of Izabal, conference general-secretary. The letter did not call for Perez to resign, but it said the "discovery of organised corruption in state institutions" has put the government in crisis. Perez has vowed to finish his term, which expires in January, while rejecting suggestions that his government is collapsing. Protests have been growing since early May when then-Vice President Roxana Baldetti resigned as prosecutors investigated whether importers allegedly bribed officials for reduced duties on shipments. Baldetti has not been charged, but prosecutors said her top aide, Juan Carlos Monzon, was behind the conspiracy. Then, in late May, 15 officials were arrested for their alleged connection to a scheme in which the Social Security Institute rigged contracts for a Mexican pharmaceutical company in exchange for millions of dollars in kickbacks. The twin scandals have forced the resignations or firing of dozens of government officials, including the head of the central bank and top ministers.