CAIRO (AP) -- Egypt postponed early voting on a contentious draft constitution, and aides to President Mohammed Morsi floated the possibility of canceling the whole referendum in the first signs Friday that the Islamic leader is finally yielding to days of protests and deadly street clashes.
Tens of thousands marched on the presidential palace after pushing past barbed wire fences installed by the army and calling for Morsi to step down. Thousands also camped out in Tahrir Square, birthplace of the uprising that toppled Hosni Mubarak in 2011.
A spokesman for Morsi's Muslim Brotherhood urged the group's supporters to practice "self-restraint" after hundreds gathered in front of a mosque near the presidential palace. He appealed for them not to march to the palace and to avoid confrontation.
The announcement by the election committee head Ismail Hamdi to delay early voting on the charter came as a surprise, and it was difficult to predict whether it will lead to a breakthrough in the political crisis.
The president's aides said the move would ease some pressure and would provide room for negotiations with the opposition.
But Morsi's opponents have rejected talks, saying he must first cancel the referendum and meet other demands. Late Friday, an opposition umbrella group called for an open-ended sit-in in front of the presidential palace.
The crisis began Nov. 22, when Morsi issued a decree that gave him absolute powers and immunity from judicial oversight. It deepened when he called for a Dec. 15 national referendum on the draft constitution hurriedly produced by the Islamist-led constituent assembly. The draft was infused with articles that liberals fear would pave the way for Islamizing Egypt.
Legal Affairs Minister Mohammed Mahsoub said the administration was weighing several proposals -- including calling off the referendum and returning it to the constituent assembly for changes. Another possibility was disbanding the constituent assembly and forming a new one, either by direct vote or an agreement among the political forces.
"We have a big chance tomorrow," Mahsoub told the Qatari-based Al-Jazeera network, referring to what he said was a meeting between Morsi and political forces. "There are no deadlines or referendums outside the country. Tomorrow or day after, we might reach a good agreement."
Vice President Mahmoud Mekki also told the broadcaster that he had contacted leading democracy advocate Mohamed ElBaradei to join Morsi in a dialogue. ElBaradei leads the newly formed National Salvation Front, a group of liberals and youths who opposed Morsi's decrees and led the protests in Cairo.
In a televised speech, ElBaradei made clear the opposition's demands: cancellation of the declaration that Morsi used to give himself immunity from judicial oversight and postponement of the referendum.
"The people are angry because they feel their rights have been raped," ElBaradei said on the ONTV network. "If he takes these decisions, he will be opening the door for dialogue. I hope he is listening."
The opposition National Salvation Front rejected talks with Morsi, urging an ongoing sit-in at the palace and warned of assaults on the protesters and more violence.
"We reject the fake dialogue which Morsi has called for. No talks after bloodshed and before holding those responsible accountable," the front said in a statement.
Some protesters expressed optimism after they heard that the early voting for Egyptians abroad, which was due to begin Saturday, had been put off until Dec. 5.
"This looks like the beginning of a retraction," said Dr. Mohsen Ibrahim, a 56-year-old demonstrator. "This means Morsi may postpone the referendum. It looks like the pressure is working out."
But he warned that "if Morsi doesn't see the numbers of people protesting, then he will be repeating the same mistake of Mubarak."
Since the Arab Spring uprising that toppled Mubarak, Egypt has been split between Islamists and mostly secular and liberal protesters. Each side depicts the conflict as an all-out fight for Egypt's future and identity.
The opposition accuses Morsi and his Islamist allies of turning increasingly dictatorial to force their agenda on the country, monopolize power and turn Egypt to a religious state. The Muslim Brotherhood and other Islamists say the opposition is trying to use the streets to overturn their victories in elections over the past year and stifle popular demands to implement Islamic Shariah law.
The tone was one of a battle cry as thousands of Islamists held funeral prayers at Al-Azhar Mosque -- the country's premier Islamic institution -- for Morsi supporters killed in Wednesday's clashes. A series of speakers portrayed the opposition as tools of the Mubarak regime, or as decadent and un-Islamic.