Mohammed Morsi became the first democratically elected president in Egyptian history last year. The military removed him from power in July amid ongoing frustration with his Islamist principles and failure to address Egypt's economic woes.
A movement calling itself a pro-legitimacy national alliance says it was calling on all Egyptians to turn out for a "massive" march on the central Cairo square Sunday.
"Participate peacefully, positively," the statement published on the Muslim Brotherhood's website said Thursday. "Egypt's coalition of parties, groups and movements opposed to the heinous coup calls all Egyptians to participate in a massive peaceful protest."
Morsi was the Muslim Brotherhood's presidential candidate. He, along with several high-ranking Brotherhood members, is behind bars.
European foreign policy chief Catherine Ashton is in Cairo this week meeting with interim political leaders and members of the opposition. The EU this year restricted military sales to Egypt in response to a military crackdown on Brotherhood supporters.