CAIRO - Egypt's president ordered parliament's upper chamber to convene after the release of official results of a referendum on an Islamist-backed constitution that gives temporary legislative powers to the traditionally toothless chamber.

The results had been expected on Monday but were not released, and the electoral commission has not yet set a date to announce them. The Muslim Brotherhood, the main group that backed the charter, said it passed with 64 percent of the vote - a result likely to be confirmed by the official result.

Parliament's upper house, the Shura Council, cannot convene before the official word that the constitution has passed.

The new constitution would give the Shura Council powers to legislate until the lower house is elected within the next two months. President Mohammed Morsi has held legislative powers for months now since a court disbanded the lower house of parliament.

Over the weekend, Morsi appointed 90 members to the Islamist-dominated Shura Council, in an attempt to make the body more representative.

The 90 include at least 30 Islamists and a dozen minority Christians. The council now has a total of 270 members, two-thirds of them elected. Critics, however, say most of the representatives are either Islamists or their supporters.

The council was elected last winter in a vote with a very low turnout - less than 10 percent of Egypt's 51 million eligible voters.

The council is expected to prioritize the passing of a new law on the rules for parliamentary elections. The former lower house was dissolved after a court order ruled the law governing election of its members was unconstitutional.