The National Alliance to Support Legitimacy, a coalition backing deposed president Mohamed Morsi, reiterated on Sunday its call to supporters to rally at the police institute where Morsi is due in court Monday.
The official statement called once again for "all Egyptians" to protest against Morsi's trial, due to be held in south Cairo's Tora.
The statement also warned against airing the trial live on TV.
It is not yet clear whether or not the 62-year-old Morsi will appear in court. However, an interior ministry official said that the ousted president will be flown to the Monday trial by helicopter.
Morsi is charged with incitement of murder and violence in the December 2012 Ittihadiya presidential palace clashes, which pitched Morsi opponents against his supporters. Fourteen others, including leading members of the Muslim Brotherhood group from which Morsi hails, are also on trial in the case.
Heavy security is expected nationwide on Monday. Some 20,000 police officers and soldiers will guard the upcoming trial.
Meanwhile, the interior ministry has warned against any attempts to attack public institutions or security forces during the widespread protests predicted for Monday.
In its Sunday statement, the Alliance assured that protests will remain peaceful and "stronger than the [police] bullets."
Pro-Morsi groups have staged regular demonstrations since Morsi's popularly-backed ouster in July. The protests have largely remained peaceful. However, scuffles frequently break out between protesters, security, and local opponents.
University campuses have also witnessed daily demonstrations as of late, some of which have escalated into violent conflict. On Wednesday, police stormed Cairo's Al-Azhar University campus to disperse student protests after clashes erupted with staff members.
In August, police forcibly dispersed two pro-Morsi sit-ins in Cairo, leaving hundreds dead. Since then, dozens of leading Muslim Brotherhood figures have been arrested, facing charges including incitement of violence.