Islamists have approved a draft constitution for Egypt without the participation of liberal and Christian members, seeking to pre-empt a court ruling that could dissolve their panel with a rushed, marathon vote that further inflamed the conflict between the opposition and the president, Mohamed Morsi.

The vote by the constituent assembly advanced a charter with an Islamist bent that rights experts say could give Muslim clerics oversight over legislation and bring restrictions on freedom of speech, women's rights and other liberties.

The draft, which the assembly plans to deliver to the president on Saturday, must be put to a nationwide referendum within 30 days. Morsi said on Thursday it would be held "soon".

The Islamist-dominated assembly, which has been working on the constitution for months, raced to pass it, voting one by one on more than 230 articles for more than 16 hours. The lack of inclusion was on display in the nationally televised gathering: of the 85 members in attendance, there was not a single Christian and only four women, all Islamists.

For weeks, liberal, secular and Christian members, already a minority on the 100-member panel, have been withdrawing to protest against what they call the Islamists' hijacking of the process.

"This constitution represents the diversity of the Egyptian people. All Egyptians, male and female, will find themselves in this constitution," Essam el-Erian, a representative of the Muslim Brotherhood, declared to the assembly after the last articles were passed just after sunrise on Friday.

The sudden rush to finish came as the latest twist in a week-long crisis pitting the Brotherhood veteran Morsi and his Islamist supporters against a mostly secular and liberal opposition and the powerful judiciary. Voting had not been expected for another two months. But the assembly abruptly moved it up in order to pass the draft before Egypt's supreme constitutional court rules on Sunday on whether to dissolve the panel.

"I am saddened to see this come out while Egypt is so divided," Egypt's top reform leader, the Nobel peace laureate Mohamed ElBaradei, said on al-Nahar TV. But he predicted the document would not last long. "It will be part of political folklore and will go to the garbage bin of history."

A new opposition bloc led by ElBaradei and other liberals said the assembly had lost its legitimacy. "It is trying to impose a constitution monopolised by one trend and is the furthest from national consensus, produced in a farcical way," the National Salvation Front said in a statement read out by Waheed Abdel-Meguid, one of the assembly members who withdrew.

Thursday's vote escalates the already bruising confrontation sparked last week when Morsi gave himself near absolute powers by neutralising the judiciary, the last branch of the state not in his hands. Morsi banned the courts from dissolving the constitutional assembly or the upper house of parliament and from reviewing his own decisions.

In an interview on state TV aired late on Thursday, Morsi defended his edicts, saying they were a necessary "delicate surgery" to get Egypt through a transitional period and end instability he blamed on the lack of a constitution.

"The most important thing of this period is that we finish the constitution, so that we have a parliament under the constitution, elected properly, an independent judiciary, and a president who executes the law," Morsi said.