Tens of thousands of protesters opposed to Egypt's president and the sweeping new powers he assumed last week are in Cairo's Tahrir Square, hours after a new constitution was hastily approved.
The Islamist-dominated constituent assembly finished voting on the draft in the early hours on Friday.
The draft will now be sent to Mr Morsi, who is expected to call a referendum.
The Supreme Constitutional Court is due to rule on Sunday on whether the assembly should be dissolved.
Senior judges have been in a stand-off with the president since he granted himself sweeping new powers.
'Fall of the regime'
An emergency decree issued last week said Mr Morsi's decisions could not be revoked by any authority, including the judiciary, until the new constitution had been ratified and a fresh parliamentary election is held.
It also stated that the courts could not dissolve the constituent assembly.
Mr Morsi says he will give up his extraordinary powers once the new constitution is approved by a referendum.
Live TV feeds from Tahrir Square showed tens of thousands of people in the square.
Demonstrators chanted slogans, including, "The people want the fall of the regime", one of the rallying cries against ex-President Hosni Mubarak, who was toppled last year.
In the city of Alexandria, supporters and opponents of Mr Morsi clashed on the streets, but there were no immediate reports of injuries.
The Muslim Brotherhood and other Islamist parties have called on their supporters to join a rally in Cairo on Saturday.
Protesters confronted Mr Morsi at Friday prayers at the al-Sharbatli mosque after the preacher defended the president's recent actions, comparing them with incidents in the life of the Prophet Muhammad.
The BBC's Jon Leyne, in Cairo, says that infuriated worshippers, who chanted against the president, while Mr Morsi himself got up to say that did not agree with the preacher.
It is an illustration of how inflamed and divided opinion is across Egypt, our correspondent says.
Mr Morsi insists the powers he has taken are meant to be temporary and will protect the transition to a constitutional democracy.
However, their extent has raised fears that he might become a new strongman.
UN Human Rights Commissioner Navi Pillay has written to Mr Morsi, asking him to reconsider his decree. In her letter, Ms Pillay "warned that approving a constitution in these circumstances could be a deeply divisive move", her spokesman said.
Mr Morsi's decree of 22 November gave the 100-member constituent assembly until January to complete the draft constitution.
Opponents filed 43 separate lawsuits challenging the process.
When the Supreme Constitutional Court said it would soon rule on the lawsuits, supporters of the president on the assembly decided to pass a rushed draft to head off the threat of dissolution.
During a marathon session that began on Thursday and continued through the night, the assembly voted on and passed all 234 articles.
Among the historic changes to Egypt's system of government, the draft limits the amount of time a president can serve to two four-year terms.
It also introduces some civilian oversight of the military establishment.
The draft keeps in place an article defining "principles of Sharia", or Islamic law, as the main source of legislation.