The upscale Cairo neighborhood of Heliopolis descended into violent chaos on Wednesday night, as thousands of Muslim Brotherhood supporters confronted opponents of Egyptian President Mohamed Morsi.

The all-night street fight represented the worst clashes since Egyptians ousted former President Hosni Mubarak in February 2011, and sparked fears of worsening chaos in a political battle between Islamists and pro-democracy activists.

Meanwhile, a Dec. 15 nationwide referendum looms on a new constitution many say is designed to enshrine Islamic rule and deepen oppression for secularists and the country’s Christian minority. One Egyptian pastor—who asked not to be identified—wrote an email on Thursday morning to Christians outside the country with the heading: “Egypt needs your help.”

Tumult has marked post-revolution Egypt since last year’s Arab Spring, but the conflict intensified on Nov. 22 when President Morsi—a member of the Muslim Brotherhood—issued a sweeping presidential declaration: The decree exempted the president’s decisions from judicial review, effectively giving Morsi power over the executive, legislative, and judicial branches of government. Opponents decried Morsi as Egypt’s “new pharaoh.”

Morsi said the decree was in effect only until Egyptians voted on a new constitution, but the constitutional process has been fraught with turmoil: Nearly 20 percent of the constitutional assembly resigned in October. The departing group of mostly secularists and Christians said hardline Islamists were hijacking the constitution to enshrine Sharia law into civic life.

Islamists confirmed those fears on Nov. 30 by suddenly announcing the constitution was complete. The body held a marathon, 16-hour session and hastily approved the document’s 230 articles. Morsi announced the country would vote on the constitution on Dec. 15. (Egyptian courts have little recourse: Morsi’s earlier decree included a provision that the courts can’t dissolve the constitutional assembly.)

The rushed document not only contains spelling and grammatical errors, it alarms critics: Opponents say the constitution doesn’t adequately protect women’s rights and it opens the door for unelected Islamic clerics to vet legislation to ensure it comports with Sharia law.

Thousands of demonstrators had filled Tahrir Square to protest Morsi’s presidential decree. By Tuesday, many of those protesters had reached Morsi’s presidential palace in Heliopolis. On Wednesday afternoon, Muslim Brotherhood leader Essam El-Eryan called on Islamists to go to the presidential palace to “defend the state and its legitimacy.” Thousands of pro-Morsi supporters descended on opposition activists who had been staging a peaceful protest.

The peace broke as Morsi supporters drove out opposition activists, and hours of violent street fights followed. The state’s Ministry of Health reported five dead and more than 600 injured from beatings, gunshot wounds, and tear gas inhalation.

By Thursday morning, Morsi supporters controlled the grounds, though Egypt’s Revolutionary Guard ordered all protesters away from the presidential palace.

Morsi has made few public statements regarding the crisis, but his vice president indicated the referendum would go forward on Dec. 15. Opponents are calling for Morsi to rescind his presidential decree and postpone the constitutional vote until a broader consensus can unfold.

In a Thursday morning email, the Egyptian pastor writing to Christians made a similar plea and described life under Morsi so far:

“The first few months of Islamist rule have been dismal. The freedom of the press has been under attack. The harassment of women and Christians is alarming. The economy and infrastructure continue to deteriorate. Weapons and other resources have been passed to Hamas in Gaza. Radical groups are threatening the stability of the Sinai Peninsula.”

The pastor called on Christians to pray for Egypt, and he pressed them to ask Western leaders: “Are we supporting freedom in Egypt? Do we want an Islamist Mideast or a truly democratic one?”

The minister said he was encouraged that “millions of Muslims are rejecting those who are using their religion as a tool for political gain. Christians are standing next to these moderate Muslims and together they are making a difference. ” But he asked: “Why is so much of Western media strangely silent or ambiguous in the message that it is sending?”

The Obama administration has been notably reserved in its approach to the crisis, though President Obama called for an end to bloodshed, and Secretary of State Hillary Clinton said Egyptians deserve a fairer constitutional process.

Whether that will happen remains unclear. While Morsi seems entrenched, he also faces enormous pressure, as members of his inner circle defect: At least six presidential advisers have resigned since the crisis began. Seif Abdel Fattah, one of Morsi’s aides, said he could “no longer stay silent because the Muslim Brotherhood has harmed the nation and the revolution.”

Opposition activists also seem determined to continue. Mohamed ElBaradei—a reform advocate—wrote in the Financial Times last week: