CAIRO: Egyptian President Mohamed Morsi assumed sweeping powers on Thursday, prompting prominent opposition figure Mohamed ElBaradei to accuse him of usurping authority and becoming a “new pharoah”.

“The president can issue any decision or measure to protect the revolution,” according to a decree read out on television by presidential spokesman Yasser Ali.

“The constitutional declarations, decisions and laws issued by the president are final and not subject to appeal.”

Morsi also sacked prosecutor general Abdel Meguid Mahmud, whom he failed to oust last month, appointing Talaat Ibrahim Abdallah to replace him.

That set him on another collision course with the country's judiciary after he last month promised to bring back to court ex-regime officials acquitted of organising an attack on protesters during last year's uprising against ousted leader Hosni Mubarak.

The president in his pronouncements on Thursday ordered “new investigations and retrials” in the cases dealing with the deaths of protesters, a decision that could net senior military officials.

He also said no judicial body can dissolve the the upper house of parliament or the Islamic parties-dominated constituent assembly that is writing a new constitution and which has been criticised by the secular-minded opposition for failing to represent all segments of society.

He has also given the body, which was due to issue a draft consitution in December, two extra months to come up with a charter, that will then be put to a referendum.

The declaration is aimed at “cleansing state institutions” and “destroying the infrastructure of the old regime.”

Nobel laureate and former UN atomic energy agency chief Mohamed ElBaradei lashed out at the declaration, which effectively puts the president above judicial oversight.

“Morsi today usurped all state powers and appointed himself Egypt's new pharaoh. A major blow to the revolution that could have dire consequences,”ElBaradei wrote on his Twitter account.

Even before the announcement was read out, Islamists had gathered outside the High Court in central Cairo demanding the “cleansing of the judiciary.”

Morsi, who belongs to the powerful Muslim Brotherhood, is the first elected president after the popular uprising that toppled Mubarak last year.