Cairo: The blacklisted Muslim Brotherhood on Sunday endorsed a proposed November 28 protest against Egypt`s "secular and military rule", but did not say whether it will take part.
Friday`s nationwide protest labelled "The Muslim Youth Uprising" has been called by the Salafi Front, an Islamist group that supports ousted president Mohamed Morsi.
Morsi was removed by then army chief and now President Abdel Fattah al-Sisi in July 2013, and in December the authorities designated his Muslim Brotherhood a "terrorist organisation".
Morsi and Brotherhood supporters have staged regular protests, but their ability to garner large numbers has dwindled amid a government crackdown that has killed hundreds and jailed thousands.
Friday`s protest call has already generated support on social networks from pro-Morsi Islamists, but has been strongly criticised in the media.
"The Muslim Brotherhood endorses this call for protests to preserve the nation`s identity, which the Egyptian people including the Muslim Brotherhood have fought for," a statement by the movement on Sunday said.
It did not explicitly say whether Brotherhood members will take part, however.
The protest is to "declare Egypt`s Islamic identity, oppose Western and Zionist domination and topple the military`s proxy rule", the Salafi Front said in a statement.
"Our demand is not just to topple Sisi, but to fight for our (Islamic) identity," the front`s spokesman Mohammed Galal told AFP.
The authorities have vowed to crush the protests.
"We will firmly face any acts of violence using the rule of law. Any violation of the law will not be taken lightly," Interior Minister Mohamed Ibrahim said last week.