Egypt's opposition called Sunday for an investigation into allegations of vote fraud in the referendum on a deeply divisive Islamist-backed constitution after the Muslim Brotherhood, the main group backing the charter, claimed it passed with a 64 percent "yes" vote.
Official results have not been released yet and are expected on Monday. If the unofficial numbers are confirmed, it will be a victory Islamist President Mohammed Morsi, who is from the Brotherhood.
But for many Egyptians, especially the tens of millions who live in extreme poverty, the results are unlikely to bring a hoped for end to the turmoil that has roiled their country for nearly two years since the uprising that ousted authoritarian leader Hosni Mubarak.
The opposition allegations look likely to prolong the struggle that has exploded in deadly street violence at times over the past month, ensuring that stability will remain elusive.
"The referendum is not the end game. It is only a battle in this long struggle for the future of Egypt," said the National Salvation Front, the main opposition group. "We will not allow a change to the identity of Egypt or the return of the age of tyranny."
The opposition claims the new constitution seeks to enshrine Islamic rule in Egypt and accuses the Islamists of trying to monopolize power.
Critics say it does not sufficiently protect the rights of women and minority groups and empowers Muslim clerics by giving them a say over legislation. Some articles were also seen as tailored to get rid of Islamists' enemies and undermine the freedom of labor unions.
The opposition front said it filed complaints to the country's top prosecutor and the election commission asking for an investigation.
"The results of the referendum are for sure because of the rigging, violations and mismanagement that characterized it," the opposition group said.
However, the Brotherhood insisted violations were limited and should not affect the referendum's integrity.
The Freedom and Justice Party, the Brotherhood's political arm, said it hoped the passage of the constitution would be a "historic opportunity" to heal Egypt's divisions and launch a dialogue to restore stability and build state institutions.
If the violations are considered serious enough, there could be new votes in some areas that alter the results slightly.
One major concern in the aftermath of the constitutional turmoil is Egypt's deteriorating economy, which has been battered by the two years of turmoil and taken an added hit from renewed violence recently.
The referendum was conducted in two stages with the first vote on Dec. 15 and the second on Saturday. The Muslim Brotherhood and some media outlets have accurately tallied the outcome of past elections by compiling numbers released by electoral officials at thousands of individual polling stations shortly after voting closes.
Turnout for the vote was 32 percent of Egypt's more than 51 million eligible voters, according to the Muslim Brotherhood. That was significantly lower than other elections since the uprising ended in February 2011. The opposition has pointed to the low turnout as well as allegations of violations in the voting to cast doubt on the legitimacy of the referendum.
The Brotherhood said 64 percent voted "yes" to the constitution in a tally of both stages of voting. For Saturday's second stage only, the Brotherhood said 71 percent of those who voted said "yes" with 99 percent of polling stations accounted for.
As expected, it was a jump from the first round of voting when about 56 percent said "yes." The provinces that voted in the second round were known for being a base for Brotherhood supporters.
Only about eight million of the 25 million Egyptians eligible to vote in the second stage — a turnout of about 30 percent — cast their ballots. Some 32 percent of eligible voters participated in the first round.
The local media has reported results similar to the Brotherhood's. State-owned Al-Ahram newspaper said in its English language online version that 16.2 million eligible voters cast their vote, and the constitution passed with a 63.96 percent. Those numbers reflected totals of the two stages of voting.
The National Salvation Front alleged the vote was marred by lack of complete judicial supervision, which led to overcrowding that pushed down the voting rate. It also charged there was interference by those who were supposed to be supervising the vote, with some instructing people to vote "yes." Many judges who traditionally supervise elections boycotted supervising the vote.
"We don't think the results reflect the true desires of the Egyptian people," Khaled Dawoud, the front's spokesman, told The Associated Press.
The Front said that regardless of the results, it welcomed the participation of many who rejected the constitution and refused to consider it a vote on Islamic law. The group vowed to continue to "democratically" work to change the constitution and praised the high turnout of women.
The Islamists say Islam is core to Egypt's identity and they view the constitution as a foundation to move forward, elect a parliament and build state institutions.
The new constitution will come into effect once official results are announced.
Once that happens, Morsi is expected to call for the election of parliament's lower chamber, the more powerful of the legislature's two houses, within two months.
The opposition said that even though it is challenging the results of the referendum, it will continue to prepare for the upcoming parliamentary elections.
Until the lower chamber is elected, the normally toothless upper house, or Shura Council, will have legislative powers.
On Sunday, Morsi appointed 90 new members to the Islamist-controlled Shura Council as part of his efforts to make the council more representative. The new appointments included at least 25 Islamists and eight Christians. They also include eight women, four of them Christians.
The opposition front said it did not want its members nominated to the Shura Council.