Call for protests
On the eve of Morsi's trial, Egypt's Al Watan newspaper released a video on its website of what it said was him speaking to unidentified individuals during his incarceration.
Dressed in a tracksuit, Morsi described his ouster as "a crime in every way". The newspaper did not say when the video was taken.
The Brotherhood has called on its supporters to stage mass protests on Monday, but the size of their demonstrations has shrunk because of heaving policing.
"We have faith that the heroic Egyptian people will not let go of their freedom, dignity and value and will instead crawl to the unfair farce of a trial to show the world they are a people ... who will never yield their commitment and legitimacy," the Brotherhood said in a statement.
Speaking to a local television channel, Interior Minister Mohamed Ibrahim warned the group: "If the Brotherhood commit any violations, they will regret it."
Riot police crushed two-Morsi protest camps on Aug. 14, and hundreds of Islamists have been killed and thousands arrested, including the Brotherhood's top leaders.
Egypt's oldest and most influential Islamist group has also been banned and its funds seized. Army chief Abdel Fattah al-Sisi, who toppled Morsi, has become immensely popular. Few doubt his victory if he runs for president.
The Brotherhood maintains Morsi's ouster was a coup that reversed the democratic gains made after Mubarak's overthrow.
Human rights groups believe the trial will indicate whether Egypt will return to democracy or accept domination by generals once again.
"(The) trial is a test for the Egyptian authorities. They should present Mohamed Morsi in court and grant him a fair trial, including the right to challenge the evidence against him in court," said Hassiba Hadj Sahraoui, Amnesty International's Deputy Director for the Middle East and North Africa Programme.
"Failing to do so would further call into question the motives behind his trial," she said, emphasising that the trial cannot proceed without Morsi's presence in court.
In the most senior visit to Cairo by a U.S. official since Morsi's fall, Secretary of State John Kerry also called for a fair, transparent trial for all Egyptians.
Egyptian officials admit the path to democracy has been rocky, but say a proper political transformation will take time.
Speaking to Reuters by phone, Osama Morsi, the deposed president's 30-year-old son, said his father had not authorised a defence lawyer and the family would not be attending the trial. "We do not acknowledge the trial. We are proud of my father and feel strong about his position."