Hundreds of protesters staging a sit-in in Tahrir have vowed not to leave before Morsi rescinds his decrees. The two sides also have called for massive rival protests Tuesday in Cairo, signaling a protracted struggle.
Morsi's office issued an English-language statement late Sunday defending his decrees and repeating the argument he used when addressing supporters Friday outside his Cairo palace — that they were designed to bolster the country's transition to democratic rule and dismantle Mubarak's old regime.
"The presidency reiterates the temporary nature of the said measures, which are not meant to concentrate powers," it said. The statement also pledged Morsi's commitment to engaging all political forces on the drafting of a new constitution. Secular and Christian members withdrew from the panel drafting the document, alleging that the Islamists who dominate the body have hijacked the process to produce a charter with an Islamist slant.
Nader Omran, of the Brotherhood's Freedom and Justice party, said any changes to the decrees were "out of the question" but Morsi might "make pledges, vows or addendums explaining his position to clarify the decrees."
He said Morsi would hand over his legislative powers to parliament's upper chamber once a new constitution is adopted in a nationwide referendum and ahead of parliamentary elections. The presidency did not confirm the claim, but doing so would leave the Egyptian leader with the state's executive and legislative powers until around April.
The move also has caused some internal discord among the Morsi camp, with one aide, Samer Marqous, already resigning to protest the "undemocratic" decree.
Another Morsi adviser Ayman al-Sayyad wrote on his Twitter account that the president met Sunday for the second time in as many days with his 17-member advisory council and three of his assistants.
"I think it (the meeting) produced a genuine realization of the gravity of the situation ... We were candid today in our meeting with the president and we now expect practical steps on the ground." He did not elaborate.
Leading Egyptian democracy advocate Mohammed ElBaradei, a Nobel Peace Laureate and a former director of the U.S. nuclear agency, warned Saturday of increasing turmoil that could potentially lead to the military stepping in unless Morsi rescinds his new powers.
Egypt's liberal and secular groups — long divided, weakened and uncertain as Islamist parties rose to power in the months after the revolution — are seeking to rally in response to the decrees as the stakes are high. The fractured opposition came together as the engine of the 18-day uprising that forced Mubarak to step down after 29 years in power, bringing millions out on the streets, but they have failed to recapture that energy after months of setbacks.
Morsi, meanwhile, already has backed down twice in high-profile battles with the judiciary in the five months he's been in office. The U.S.-trained engineer failed to challenge the court ruling dissolving parliament's powerful lower chamber and had to rescind his decision to fire the country's attorney-general, Mubarak-era appointee Abdel-Maguid Mahmoud, in October. He fired him on Thursday as part of his edicts.
Associated Press writer Aya Batrawy contributed to this report.