Egypt's Muslim Brotherhood says its candidate has won a presidential runoff vote, while the ruling military has issued an interim constitution handing itself sweeping powers after a court dissolved the Islamist-led parliament.

The Brotherhood announced Monday Mohammed Morsi defeated Ahmed Shafiq, a Mubarak-era representative whose aides also claimed their candidate was in the lead after polls closed Sunday night.

The Brotherhood has warned it would launch protests if Mr. Shafiq is declared the winner.

Turnout appeared low compared with the 46 percent reported in last month's first round – a sign of dampening morale as the military tightened its grip on power.

According to military sources, the interim constitution would grant the Supreme Council of the Armed Forces exclusive legislative powers in addition to control of the nation's budget until a new parliament is elected. The decree also gives the military the authority to compose its own 100-member panel that would draft Egypt's new constitution.

Egyptian state television reported late Sunday that the military council would explain the widely anticipated declaration at a news conference Monday.

The lack of turnout for the presidential vote likely also reflects dissatisfaction with the choice of candidates. Mr. Shafiq is a former air force general and confidant of former president Hosni Mubarak, who was ousted in an uprising last year. Mr. Shafiq promised to restore order and push back against the rise of Islamism. Mr. Morsi represents the once-outlawed Muslim Brotherhood, a religious party committed to reversing liberal social traditions.

Many of Egypt's 50 million eligible voters saw neither man as an acceptable choice. Some cast ballots against both candidates in a sign of protest.

Voters shared with VOA Sunday their disillusionment about the stark differences between the two contenders, as the first round eliminated centrist candidates.

The announcement of the winner as Egypt's first freely elected president is set for Thursday, but unofficial results are expected sooner.

Last week's Supreme Constitutional Court ruling to dissolve the country's current parliament led to accusations from some leading Islamists and liberals that the military is instituting a de facto coup through the judiciary.

The official MENA news agency said parliament received notice of the decree Saturday and that lawmakers will be barred from entering parliament, except with permission.