Egypt's opposition has called for more protests against President Mohamed Morsi after rejecting his plans for a constitutional referendum later this week on a disputed draft constitution.
"The National Salvation Front announces its total rejection of the referendum and will not legitimise this referendum which will definitely lead to more strife," Sameh Ashour, who spoke on behalf of the coalition of opposition parties, said on Sunday.
"The Front invites Egypt's great people to protest peacefully in various liberation squares in the capital this coming Tuesday to show dissatisfaction at the president's disregard of the people's demands and in refusal of the constitution that infringes on rights and freedoms."
Morsi's decision on Saturday to retract a decree awarding himself wide powers failed to placate opponents who accused him of plunging Egypt deeper into crisis by refusing to postpone the vote on the constitution scheduled for November 15..
"We are against this process from start to finish," Hussein Abdel Ghani, spokesman of the National Salvation Front, said.
The Egyptian president insists on holding the referendum on schedule.
The opposition has repeatedly said that the constitution, drafted by a Muslim Brotherhood-led constituent assembly, disregards the rights of women and ignores personal freedoms.
"I cannot imagine that after all this they want to pass a constitution that does not represent all Egyptians," Ahmed Said, another member of the National Salvation Front coalition and the head of the liberal Free Egyptians Party, said.
The referendum has deeply polarised Egypt and sparked some of the bloodiest clashes between Morsi supporters and opponents since he came to power in June.
The Egyptian president has ordered the military to maintain security and protect state institutions until the results of the referendum are announced.
"Holding a referendum now in the absence of security reflects haste and an absence of a sense of responsibility on the part of the regime, which risks pushing the country towards violent confrontation," a statement from the Front said.
The Muslim Brotherhood and its political wing Freedom and Justice party, as well as Salafist political parties, have urged the opposition to accept the referendum's verdict.
Mahmud Ghozlan, a Brotherhood spokesman, said a coalition called the Alliance of Islamist Forces have also called for a demonstration on Tuesday under the slogan "Yes to legitimacy" in support of the referendum.
The rival rallies in the capital Cairo raise the potential for clashes such as those that erupted last Wednesday, killing seven people and wounding hundreds.
The current turmoil started after Morsi’s November 22 decree and then hastily approving the constitution that was opposed by liberals, including minority Christians.