Journalist Ibrahim Eissa, a staunch opponent of Hosni Mubarak, will testify in the former president's retrial on Sunday.
Also testifying on Sunday is Brigadier General Ayman Fahim of the Republican Guard. The session will be the first to be open to the media since September, when journalists were banned for security concerns.
In front of the court at the police academy in New Cairo, around ten people gathered holding pictures of Mubarak and army chief Abdel-Fattah El-Sisi.
Mubarak, Al-Adly and six former security aides are being retried over charges of complicity in the killing of peaceful demonstrators in the 2011 revolution.
A number of officials have been summoned to give testimony, including retired military chief Field Marshal Hussein Tantawi, ex-chief of staff Sami Anan, former head of military police Hamdy Badeen, ex-spy chief Mourad Mowafi, ex-military commander for the Cairo area Hassan El-Roueini, Mubarak-era premier Ahmed Nazif and former oil minister Sherif Ismail.
Top government and military officials will continue to testify until Monday - but it is unknown whether tomorrow's session will be open to the media.
Mubarak and El-Adly both received life sentences in June 2012 on charges of political responsibility for the killing of peaceful protesters during the January 2011 uprising that led to Mubarak's ouster.
The verdicts were overturned in January 2013 by an appeal court on the grounds of procedural irregularities.
The 85-year-old deposed president also faces charges of squandering public funds by selling natural gas to Israel at below market prices.
He was released from jail in August but has been kept under house arrest at a military hospital in Maadi, a Cairo suburb.