Egypt's highest body of judges has called the president's recent decrees an "unprecedented assault on the independence of the judiciary and its rulings".
In a statement carried on MENA, the country's official news agency, the Supreme Judicial Council said they regret the declarations President Mohammed Morsi issued on Thursday.
The council is packed with judges appointed by former President Hosni Mubarak. It regulates judicial promotions and is chaired by the head of the Court of Cassation.
The judges released their statement following an emergency meeting today, a day after tens of thousands of Egyptians demonstrated to denounce Mr Morsi's decision.
The edicts give him near-absolute power and immunity from appeals in courts for any decisions or laws he declares until a new constitution and parliament is in place.
Leading democracy advocate Mohammed ElBaradei said dialogue with Egypt's Islamist president was not possible until he rescinds his decrees giving himself near absolute powers.
Mr ElBaradei said he is hoping for a "smooth transition without plunging the country into a cycle of violence".
But he said that may not be possible unless Mr Morsi rescinds the decrees.
Mr ElBaradei, a Nobel Peace laureate for his past work as the head of the UN nuclear watchdog, has formed a National Salvation Front with other liberal and secular leaders, trying to unify the opposition against Mr Morsi.