Amnesty International has called on Egyptian authorities to ensure that ousted president Mohamed Morsi appears in court and has access to all available resources for his defence.
Morsi is due in court on Monday on charges of inciting violence and murder during the December 2012 Ittihadiya presidential palace clashes, which pitted Morsi supporters against his opponents. Another 14 defendants will be tried, including senior Islamists and members of the Muslim Brotherhood's political wing, the Freedom and Justice Party.
"Tomorrow's trial is a test for the Egyptian authorities," said Hassiba Hadj Sahraoui, Amnesty International's deputy director for the Middle East and North Africa programme.
The Sunday statement, issued one day ahead of the highly-anticipated trial, called for a fair trial that would allow Morsi the right to a lawyer and to challenge evidence against him in court.
"Failing to do so would further call into question the motives behind his trial," Sahraoui wrote.
Morsi has refused to recognise the legitimacy of the court trying him, declining his right to a lawyer. His supporters have deemed the trial a "farce" and "absurd," vowing to rally nationwide and in front of Egypt's embassies and consulates on Monday.
The National Alliance to Support Legitimacy, a pro-Morsi Muslim Brotherhood-led coalition, described the trial as a "null, illegal" measure against the country's first freely elected president.
It is unclear whether or not Morsi will appear in court, but if so, it will be his first public appearance since he was ousted in July. The trial will take place at the police academy in New Cairo.
"The trial cannot proceed without Mohamed Morsi's presence in court. Everyone has a right to be present at their trial," Sahraoui stated.
"Amnesty International also has concerns that justice is being undermined due to irregularities in the legal process in the trials of other Muslim Brotherhood leaders," the statement added.