Saad al-Katatni, secretary general of the the Muslim Brotherhood's Freedom and Justice Party, attends a news conference at the headquarters of the party in Cairo on Monday. A temporary power-sharing agreement would install one of their candidates as parliamentary speaker in Egypt. (Mohamed Abd El-Ghany /Reuters)

Liberals and Islamists in Egypt announced a temporary agreement Monday on a power-sharing plan that would install a Muslim Brotherhood leader as speaker of the country’s newly elected parliament.

The agreement among six political parties all but guarantees that the Muslim Brotherhood’s Freedom and Justice Party will lead Egypt’s first elected parliament since the ouster of Hosni Mubarak in February, with the Islamist party expected to control as many as half the seats.

Under the power-sharing agreement, the ultraconservative Salafist Nour party and the liberal al-Wafd party would also claim top positions, with their representatives serving as deputy speakers, the parties announced during a news conference Monday at the Freedom and Justice Party’s headquarters.

With a week left until the lower house of the parliament meets, the Freedom and Justice Party said its nominee for speaker would be Mohamed Saad Katatny, the party’s secretary general.

During the announcement, the party heads said the agreement would be a temporary alliance to put their voting weight behind agreed-upon candidates for the parliament’s leadership positions.

“This is a one-day agreement for the day the parliament opens,” Mohamed Abou el-Ghar, the head of the Egyptian Social Democratic Party said in an interview. “We have to cooperate so the main posts in the parliament are distributed fairly to all parties, including the people who won the elections.”

Abou el-Ghar said it was possible that his own party could still be allotted one of the deputy positions if the Wafd party chose not to go along with the accord. The Social Democratic Party is part of an alliance of liberals and leftists that is expected to take the fourth most seats after the Freedom and Justice Party, the Nour party and al-Wafd.

This week the agreed parties will begin discussions to divvy up the chairmanships of political committees in the lower house of the parliament, known as the People’s Assembly. On Monday, the body will convene for the first time.

Final results of the elections are expected this week, but party projections and early returns show that Islamists are expected to take about two-thirds of the seats, most of which will go to the political wing of the historic Muslim Brotherhood organization.

The powers of the People’s Assembly are unclear and will be laid out in a still-unwritten constitution. The People’s Assembly is supposed to choose members of a constituent assembly that will write the country’s constitution.

But Egypt’s military rulers have made clear that they would like to oversee the constitution-writing process and possibly influence the selection of the constituent assembly. Political party leaders said the ruling generals would have no influence over the selection of parliament leaders.

The head of the Freedom and Justice Party, Mohammed Morsi, said during the news conference that the short-term agreement was to guarantee a “parliament that expresses national unity.”