The early results are based on reports from returning officials from the majority of stations after two rounds of voting that ended with a final ballot on Saturday. Official results, however, are not expected until Monday.

Exit polls from the opposition National Salvation Front (NSF) also showed the constitution passing, an official said. However, the opposition alleged in a statement that ballot fraud had taken place since the polls opened.

The December 15 first round returned 57 percent in favor of the constitution, according to unofficial data.

Late on Saturday, Mursi announced the names of 90 new members he had appointed to the upper house of parliament, state media reported, and according to the Muslim Brotherhood’s website the list was mainly liberals and other non-Islamists.

“President Mursi issues a Decree to approve 90 nominees for membership of Shura Council – the upper chamber of Egyptian Parliament – including 12 Coptic Christians, and a total of 75% non-Islamists,” according to the Brotherhood’s website.

Two-thirds of the 270-member upper house was elected in a vote early this year, with one third appointed by the president.

Meanwhile, Egypt’s vice-president announced his resignation even as voters were still going to the polls on Saturday, state TV reported.

Mursi’s vice president, Mahmud Mekki, whose post is not mentioned in the new charter, announced Saturday in a press statement that he was resigning.

“Political work does not suit my professional character,” he said in a statement, referring to his past as a respected judge.