Islamist movement and political forces to demand justice against police and officials linked to Hosni Mubarak Egypt’s military-backed transitional government is bracing itself for the largest protest yet against its rule on Friday as a million-strong rally to defend the revolution prepares to descend on Cairo’s Tahrir Square. In a rare show of unity, Egypt’s largest political Islamist movement, the Muslim Brotherhood, will join a vast array of liberal, leftist and secular political forces, including youth representatives from this year’s anti-Mubarak uprising. They will demand that police officers and former regime officials are finally held accountable and that the army’s grip over the justice system comes to an end. “Take to the streets on July 8: the revolution is still on,” reads graffiti which has been scrawled across the Egyptian capital. The demonstration comes at a perilous time for the authorities, following 10 days of street violence in Cairo and Suez as public frustration at the slow pace of reform begins to grow. On Wednesday, armed security forces fought running battles with civilians, after several police officers accused of murdering protesters during the toppling of former president Hosni Mubarak earlier this year were released on bail. “The demands of the revolution have not changed since day one,” declared the 25th January Revolution Youth Coalition in an online statement calling on Egyptians to join Friday’s demonstration. “It was not just about toppling the old regime but about building a state where people can have freedom, dignity, rule of law and social justice.” The Muslim Brotherhood initially said it would boycott the rally due to disagreements with political rivals over whether a new constitution should be written before or after parliamentary elections. But the “constitution-first” demand has now been softened by rally organisers and the Brotherhood’s involvement, which analysts believe is essential if the group wants to maintain credibility, looks set to bolster protester numbers significantly. The government has urged demonstrators to “maintain the peaceful nature of the protest” and warned against “plots aiming to incite chaos in order to tarnish the country’s image”. Security officials have indicated that riot police will be kept away from Tahrir Square and deployed only in side streets, supposedly in an effort to avoid confrontation. In another apparent attempt to appease the public ahead of the rally, interim interior minister Mansour al-Essawy has promised to purge up to 700 corrupt senior officers from the police force as part of the largest reshuffle in the interior ministry’s history. But five months on from the protests that led to Mubarak’s fall and left almost a thousand dead, only a single officer has been convicted of wrongdoing – and he is yet to be put behind bars. “The problem is that the revolution has ousted President Mubarak but not his regime,” said prominent author Alaa al-Aswany in a newspaper column this week – one of many decrying the continuing presence of Mubarak-affiliated ministers, judges, security officials and journalists among the country’s political elite. “The Egyptian revolution is now going through a critical moment, a real fork in the road. It can either win and accomplish its goals or (heaven forbid), it can also lose, leaving the old regime to return in a slightly different form,” said al-Aswany. “This is why the demonstrations are important… to correct what went wrong with the revolution … We will go to the square ready to pay the price of freedom. We will be like we were during the revolution, ready to die at any moment.” Activists believe the rally could help challenge the military’s legitimacy through innovative new forms of grassroots political participation, including a “civil referendum” which will see questionnaires about Egypt’s future distributed among demonstrators and dropped in manned ballot boxes throughout the square. . Young Egyptians have been using Twitter to swap techniques for getting past parental bans on attending the protest, using the hashtag ‘#fokakmenahlak’, an Arabic word meaning “split from your family”. Egypt Middle East Africa Arab and Middle East unrest Protest Muslim Brotherhood Jack Shenker guardian.co.uk