Head of Ghad Al-Thawra party, Ayman Nour, has called on General Abdel Fattah Al-Sisi to "withdraw his call for protests on Friday or take off his military uniform and engage in political work."
In wake of Al-Sisi's announcement, Nour tweeted that the army chief should either distance himself from politics or the armed forces.
On Wednesday Al-Sisi called on the Egyptian people to take to the streets on Friday to authorise him to fight "potential terrorism."
While Al-Sisi's remarks were welcomed by Tamarud (Rebel) movement and other anti-Morsi groups, they were taken as a threat by pro-Morsi supporters and many parties opposing the coup.
The remarks were understood by many as a call for a civil war. Prominent academic and politician Dr Saif Abdel Fattah called it a "prescription for chaos. History will record that the defence minister called for a civil war."
It is likely that Nour read the veiled threat behind the 'authorisation call' and therefore called on Al-Sisi to withdraw his remarks.