Tens of thousands of protesters staged a mass demonstration in Cairo after a draft constitution was agreed by an Islamist-led assembly.
Campaigners say the charter undermines the rights of women and religious minorities, as well as freedom of speech, while opponents of President Mohamed Morsi say it was rushed through to force an early referendum.
Mr Morsi, who is due to be handed the draft on Saturday, is expected to call for a referendum within two weeks.
The protests centred on Cairo’s Tahrir Square – the focal point of the uprising that toppled President Hosni Mubarak in 2011.
The crowds chanted ‘down with the constitutional assembly’ and ‘the people want to bring down the regime’.
An opposition leaflet distributed in Tahrir urged protesters to stay into Saturday, when Mr Morsi’s supporters are due to stage their own demonstrations elsewhere in the capital.
There has been a sit-in in the square for a week since Mr Morsi issued a decree, placing his decisions beyond judicial review and giving himself sweeping powers, although he says these will expire once the constitution is ratified.
The decree also prevented the constitutional court from ruling on the legality of the Islamist-dominated assembly, as it was meant to do on Sunday.
The draft constitution was passed after a marathon session lasting almost 20 hours.
It retains the ‘principles of Islamic law’ as the main source of legislation, but a new clause setting out how these should be interpreted has been criticised by Egypt’s Christian minority.
The document also limits the president to eight years in office, after Mubarak served for three decades.
Opposition leader Mohamed ElBaradei dismissed the document, saying ‘its fate will be the dustbin of history’.
Joe Stork, Middle East director for Human Rights Watch, added: ‘Rushing through a draft while serious concerns about key rights protections remain unaddressed will create huge problems down the road that won’t be easy to fix.’
Meanwhile, several independent newspapers said they would not publish an edition on Tuesday in protest.
Two people have been killed and hundreds injured in protests since Mr Morsi issued the decree on November 22.