Egyptian President Mohamed Morsi has caused controversy by putting himself above oversight and protecting Islamist lawmakers who support him.
President Morsi Thursday declared that his decisions cannot be appealed by the courts or any other authority, citing a need to "protect the revolution."
The decree announced by his spokesman also bars Egypt's judiciary from dissolving the upper house of parliament and an assembly drafting a new constitution - two bodies dominated by Morsi's Islamist allies.
In addition, he ordered retrials of former officials who used violence in efforts to suppress last year's popular revolution against longtime president Hosni Mubarak.
Morsi's supporters hailed the decision, saying it was long overdue. But the opposition called the move illegal and is planning a protest Friday. The president's action comes after he received international praise for mediating a Gaza cease-fire.
Nobel laureate Mohamed AlBaradei said Morsi has usurped all state powers, warning that there could be dire consequences. The liberal politician is a leading opposition figure in Egypt and a former head of the International Atomic Energy Agency.
Egyptian courts have been examining cases demanding the dissolution of both assemblies. But Morsi's decree effectively neutralizes the judiciary system in favor of the ruling Muslim Brotherhood.
The announced retrials for those suspected of involvement in the killings of protesters during the 2011 uprising, could include a retrial of former president Hosni Mubarak. The ousted leader was sentenced to life in prison in June for failing to stop the killings. But, he avoided convictions on more serious offenses of corruption and ordering the deadly crackdown, angering many Egyptians.
Other Mubarak-era officials and security personnel also have been acquitted on charges of killing protesters, prompting critics to accuse the top government prosecutor of mishandling the cases. In his decree Thursday, Morsi fired that prosecutor, Abdel-Maguid Mahmoud, a Mubarak appointee who had been in the post for many years. The decree retroactively limited Mahmoud's term to four years, bringing it to an immediate end.
President Morsi had tried to fire Mahmoud last month but was blocked by the courts. He named Talat Abdullah as the government's new general prosecutor.