CAIRO — Protesters flooded Cairo’s Tahrir Square on Friday in the second giant rally this week, angrily vowing to bring down a draft constitution approved by allies of President Mohammed Morsi, as Egypt appeared headed toward a volatile confrontation between the opposition and ruling Islamists.
The protests have highlighted an increasingly cohesive opposition leadership of prominent liberal and secular politicians trying to direct public anger against Morsi and the Islamists — a contrast to the leaderless youth uprising last year which toppled autocrat Hosni Mubarak.
The opposition announced plans for an intensified street campaign of protests and civil disobedience and even a possible march on Morsi’s presidential palace to prevent him from calling a nationwide referendum on the draft, which it must pass to come into effect. Top judges announced Friday they may refuse to monitor any referendum, rendering it invalid.
If a referendum is called, ‘‘we will go to him at the palace and topple him,’’ insisted one protester, Yasser Said, a businessman who said he voted for Morsi in last summer’s presidential election.
But Islamists are gearing up as well.
The Muslim Brotherhood, from which Morsi hails, drummed up supporters for its own mass rally Saturday. Islamists boasted their turnout would show that the public supports the push by the country’s first freely elected president to quickly bring a constitution and provide stability after nearly two years of turmoil.
Brotherhood activists in several cities passed out fliers calling for people to come out and ‘‘support Islamic law.’’ A number of Muslim clerics in Friday sermons in the southern city of Assiut called the president’s opponents ‘‘enemies of God and Islam.’’
The week-old crisis has already seen clashes between the two camps that left two dead and hundreds injured. On Friday, Morsi opponents and supporters rained stones and firebombs on each other in the Mediterranean city of Alexandria and the southern city of Luxor.
The Islamist-led assembly that worked on the draft for months passed it in a rushed, 16-hour session that lasted until sunrise Friday.
The vote was abruptly moved up to pass the draft before Egypt’s Constitutional Court rules on Sunday whether to dissolve the assembly. Liberal, secular, and Christian members had already quit the council to protest what they call Islamists’ hijacking of the process.
The draft is to be sent to Morsi on Saturday to decide on a date for a referendum, possibly in mid-December.
The draft has a distinctive Islamic bent — enough to worry many that civil liberties could be restricted, though its provisions for enforcing Sharia, or Islamic law, are not as firm as ultraconservatives wished.
Protests were first sparked when Morsi last week issued decrees granting himself sweeping powers that neutralized the judiciary.
Morsi said the move was needed to stop the courts — where anti-Islamist or Mubarak-era judges hold many powerful posts — from dissolving the assembly and further delaying Egypt’s transition.
But opponents accused Morsi of grabbing near-dictatorial powers by sidelining the one branch of government he doesn’t control.
Anger at Morsi even spilled over into a mosque where the Islamist president joined weekly Friday prayers. In his sermon, the mosque’s preacher compared Morsi to Islam’s Prophet Mohammed, saying the prophet had enjoyed far-reaching powers as leader, giving a precedent for the same to happen now.
‘‘No to tyranny!’’ congregants chanted.
Morsi took to the podium and told the worshipers that he too objected to the language of the sheik and that one-man rule contradicts Islam.
Friday’s crowd in Tahrir appeared comparable in size to the more than 200,000 anti-Morsi protesters who thronged the central plaza three days earlier. Tens of thousands more marched Friday in Alexandria and other cities.