Revolutionary activists are preparing for a massive demonstration in Tahrir Square Tuesday to demand a retrial for former President Hosni Mubarak and former Interior Ministry senior officials on charges of involvement in killing protesters during the 25 January uprising. Dozens of protesters marched around the square Tuesday morning before the mass demonstration began. On Saturday, a Cairo criminal court sentenced Mubarak and former Interior Minister Habib al-Adly to life in prison for failing to prevent the murder of pro-democracy protesters during the 18-day revolt that forced Mubarak to step down. The court also exonerated six former senior security officials on the same charges. Mubarak's two sons, Alaa and Gamal, and businessman Hussein Salem were found innocent of separate financial corruption charges. The Tuesday demonstration will also demand the application of the military government-approved Political Isolation Law, which would prevent former Prime Minister Ahmed Shafiq from competing in the presidential runoff on 16 and 17 June. Protesters intend to call for the formation of a presidential council comprising prominent pro-revolution figures to replace the Supreme Council of the Armed Forces two weeks before the election is set to take place. Shafiq and Muslim Brotherhood candidate Mohamed Morsy both reject the idea, saying the winner of the runoff election will be the legitimate president of the country. Tahrir Square, which was the axis of the January 2011 uprising, has seen mass protests since the verdict was issued. Edited translation from Al-Masry Al-Youm