Egypt's opposition said on Sunday it will appeal a referendum on a new constitution backed by ruling Islamists, and vowed to keep up a struggle that has spawned weeks of protests and instability.
Polling "fraud and violations" skewed the results of the two-stage referendum, the final leg of which was held on Saturday, the National Salvation Front charged, according to an AFP report.
"We are asking the (electoral) commission to investigate the irregularities before announcing official results," a Front member, Amr Hamzawy, was quoted as having told a Cairo news conference.
"The referendum is not the end of the road. It is only one battle," said another member, Abdel Ghaffar Shokr, reading from a Front statement. "We will continue the fight for the Egyptian people."
Exit polls showed that Egyptians approved the new constitution in this weekend's nationwide referendum. According to initial reports from Egyptian state media, approximately 63 percent of voters supported the new document.
A member of the national electoral commission, Mohamed el-Tanobly, told AFP that "no official date has been fixed" for the publication of the final referendum results.
The state news agency MENA had reported they would be released on Monday.
Germany immediately backed the opposition's call for a transparent investigation into the results, reported AFP. Foreign Minister Guido Westerwelle said, "The new constitution can only meet with acceptance if the process of its adoption is beyond reproach."
Westerwelle said it was "not the power of the street but rather the spirit of compromise and tolerance that should determine the way forward for Egypt."
Opposition to the charter has fuelled demonstrations for the past month, some of them violent, such as clashes that wounded 62 people in Egypt's second city of Alexandria on Friday, the day before the final round of voting.
Late Sunday, unidentified people threw stones at the head of the judges' club, Ahmed Zind, after a meeting in which he denounced an "attack on the judicial process" by "a party that thinks of itself as king of Egypt," a judicial source said.
This was seen as a reference to the Brotherhood, from which Morsi hails.
The army has deployed troops to reinforce police since December 5 clashes outside the presidential palace in Cairo killed eight people and injured more than 600 others.
Morsi and Islamists backing the charter say it is necessary to restore stability after the early 2011 revolution that toppled president Hosni Mubarak.
The opposition sees the new constitution as a wedge to usher in creeping Islamic law through a weakening of human rights, particularly women's rights, and undermine the independence of the judiciary.
It accuses Morsi of steamrolling through the referendum without consensus on the charter, and argues that a low voter turnout of around 32 percent undermined the plebiscite's legitimacy.
As Egyptians voted in Saturday's referendum, the country's Vice President Mahmud Mekki announced his resignation.
Mekki said he was stepping down because "political work does not suit my professional character as a judge."