CAIRO - Egypt's chief public prosecutor, forced to quit this week after opposition protests, retracted his resignation on Thursday, setting the stage for more turmoil as the nation votes in a referendum on its political future. Prosecutor Talaat Ibrahim, appointed by President Mohamed Mursi when he assumed sweeping new powers last month, said he had changed his mind because his resignation on Monday had been offered under duress. Ibrahim had quit after more than 1,000 members of his staff gathered at his office in Cairo to demand that he step down. Mursi's decision to appoint Ibrahim, instead of leaving the appointment to judicial authorities, threatened the independence of the judiciary, the angered prosecutors said. Ibrahim described his removal from office as "mysterious and abnormal" and said it was now up to the justice minister to decide on his future, according to the state-run al-Ahram news website. Several prosecutors immediately announced they were suspending work and would stage an open-ended protest outside Ibrahim's office. Ibrahim's about-face came 48 hours before Egyptians vote in a referendum on a divisive new constitution championed by Mursi as a vital step in Egypt's transition to democracy almost two years after the fall of Hosni Mubarak. The opposition, facing defeat over the constitution, urged voters to reject the Islamist-backed charter and pledged to fight on to amend it during elections expected next year. The opposition, a coalition of liberals, leftists, Christians and secular Muslims, called for a "no" vote against a document it views as leaning too far towards Islamism. The first day of voting on December 15 resulted in a 57 percent majority in favor of the constitution. The second stage on Saturday is expected to produce another "yes" vote as it covers regions seen as more conservative and likely to back Mursi.