Nasser Nasser, Associated Press
An Egyptian man carrying a child passes by traditional lanterns on display for sale at a street in Cairo, Egypt Monday, July 18, 2011. Egyptians shop for lanterns in preparation for the upcoming Muslims holy month of Ramadan beginning early August this year, to decorate their houses, shops and streets giving Egypt colorful and distinguished nights among the Islamic world.

CAIRO — Egypt's military rulers commissioned a top judge Monday to form an electoral commission, starting the process of organizing the country's first elections after the popular uprising that ousted authoritarian leader Hosni Mubarak.

The military decree effectively sets a timeframe for the first parliamentary elections in Egypt's transition to democracy. The commission begind work on Sept.18, with the vote expected to follow roughly two months later, according to human rights lawyers. The decree, reported by the state news agency, did not set an exact date.

The decision settles a major dispute among various political factions over whether elections should come before or after the writing of a constitution. Many liberals fear well-organized Islamist groups are poised to win big in parliament and hence influence the writing of the country's post-revolution constitution.

"This is a strong indication that the military council is still committed to holding elections first," said Hafez Abou Saada, the head of the Egyptian Organization for Human Rights, which monitored previous elections.

As an apparent compromise, the ruling military council said it will prepare a document that would introduce guiding principles to prevent any one group from heavily influencing the new constitution.

The council has said it will transfer power to an elected civilian government within six months of taking over the country's affairs in February, when Mubarak was ousted. But they have not yet adopted an election law, which sets procedures.

The military designated the head of the Cairo Appeals Court to begin forming the electoral commission. According to law, the acting head of that court presides over the commission. Currently, Judge El-Sayed Omar heads the court. The commission will prepare voter rosters, candidate lists and oversee a one-month campaigning period.

Also Monday, the prime minister postponed the swearing-in of his new Cabinet for further consultations.

Essam Sharaf named 13 new ministers and two deputies under pressure from protesters demanding a purge of remnants of the former regime. They were expected to be sworn in Monday before the military rulers.

The state news agency said Sharaf has postponed the ceremony for consultations with other ministers. It gave no date for the new ceremony.

State television dubbed the new government "The Revolution Cabinet" but many protesters still saw the changes as insufficient.

Tension has been on the rise in Egypt over what many perceive as the military rulers' reluctance to act against Mubarak and his loyalists. In one of the most sustained campaigns to pressure the military since they took charge in February, protesters have camped out in Tahrir for nearly two weeks demanding an overhaul of government.