Egyptian President Mohamed Morsi has called on Egyptians to vote on December 15 in a referendum on a controversial draft constitution at the heart of recent political tensions.
It comes after up to 200,000 Islamist backers of Mr Morsi staged a mass rally in Cairo in support of his expanding powers and the drafting of a new constitution.
"The Muslim Brotherhood supports President Morsi's decisions," read a banner carried by supporters who chanted: "The people want the implementation of God's law."
Speaking after receiving the final draft of the constitution from the Islamist-dominated assembly, Mr Morsi urged a national dialogue as the country nears the end of the transition from Hosni Mubarak's rule.
"I renew my call for opening a serious national dialogue over the concerns of the nation, with all honesty and impartiality, to end the transitional period as soon as possible, in a way that guarantees the newly-born democracy," Mr Morsi said.
The politician plunged Egypt into a new crisis last week when he issued a decree placing his decisions beyond judicial challenge and gave himself sweeping powers.
Its new Muslim Brotherhood President said it was a temporary measure to speed-up Egypt's democratic transition until the revised charter was in place.
Saturday's demonstration in the heart of the capital comes a day after tens of thousands converged on Tahrir Square to protest against Mr Morsi's decree and the speedy adoption of the draft constitution which they see as a dictatorial power grab.
Mohamed Noshi, 23, a pharmacist from Mansoura, north of Cairo, said: "Those in Tahrir don't represent everyone. Most people support Morsi and aren't against the decree."
"There are people who want instability," said another demonstrator, referring to anti-Morsi protesters.
"There needs to be a constitution for there to be stability."
The final draft of the constitution was adopted after a marathon overnight session on Thursday that was boycotted by liberals, seculars and Christians.
They are opposed to the haste in which the charter has been adopted and some of its provisions on rights and freedoms.
Heba Morayef, Human Rights Watch Egypt directors, said some of the draft articles on freedom of expression and religion resemble a "penal code".
"Some of the provisions are penal code provisions. You don't list all the things that you are not allowed to do, you're supposed to set up the rights and limitations," she said.
Pro-Morsi protests are also taking place in Nahdet Misr Square in Giza, on the outskirts of Cairo, Alexandria and the central Egyptian province of Assiut.
The Muslim Brotherhood and their supporters have branded the opposition as enemies of the revolution that toppled longtime dictator Mubarak in 2011.