Members of Parliament attend a parliament session in Cairo February 26, 2012. Egypt's military rulers invited the parliament's two houses to convene on Saturday to elect an assembly tasked with writing the country's first constitution since the overthrowing of former President Hosni Mubarak. (AMR ABDALLAH DALSH/REUTERS)

Egypt’s new lawmakers on Saturday began discussing the makeup of an assembly responsible for rewriting the country’s constitution, embarking on their most consequential task so far.

The process could drastically change the way the Arab world’s most populous nation is governed and determine the role of Islam in policymaking. Also at stake is the balance of power between the new president and the judicial and legislative branches, an issue that looms large after three decades of autocratic rule under former president Hosni Mubarak and the turbulent months that followed his ouster last year.

The debate Saturday centered on who should be appointed to the 100-member assembly that will pen the document. Lawmakers were at odds over whether most of the participants should be members of parliament or non-elected public figures, intellectuals and union leaders.

The assembly will be selected March 24, parliament members declared after an hours-long meeting aired live on Egyptian television.

“For the first time, real sections of Egypt’s society are participating in writing the nation’s constitution,” said Ziad Akl, a political science professor at the American University in Cairo. Akl said the most important debates will focus on the nation’s identity as an Islamist state, the role of the powerful military and social issues, such as freedom of speech and religion.

The newly elected parliament is dominated by Islamist politicians from the relatively moderate Muslim Brotherhood’s Freedom and Justice Party and the ultra-conservative Salafist party al-Nour. The Salafists, the second-largest group in parliament, say Islam should be the sole source of legislation, despite support among other lawmakers for an article in the current constitution that makes it the “principal source.”

Muslim Brotherhood politicians will probably dominate the process, which must be completed in time to put a draft constitution to a referendum before the presidential elections, which are scheduled to begin May 23.

Many political activists worry that the military’s ruling generals are pressuring parliament to force the constitution through before a president is elected so that they can protect their political and economic interests.

“All Egyptians are worried about the interference of the Supreme Council of the Armed Forces,” said Rana Farouk of the Revolution Youth Union, a youth advocacy group. “We want a president first.”

Parliament member Mahmoud Khodairy, a former judge who won an independent seat and is backed by the Freedom and Justice Party, said neither the public nor parliament would allow the military to interfere in the drafting of the constitution. He acknowledged that the Brotherhood would set the tone as the dominant force in parliament but stressed the importance of including women, Coptic Christians and professionals in the process. Fewer than 2 percent of lawmakers are women.

“We will not accept military interference,” he said. “The people will approve the constitution if the Muslim Brotherhood and the Nour Party accept it.”

Saturday’s constitution meeting, however, was overshadowed by continued outrage over the government’s handling of a criminal investigation into the work of foreign pro-democracy groups.

On Thursday, American and other foreign pro-democracy workers accused of working in the country illegally were allowed to fly out of Egypt on a chartered plane after the groups paid millions of dollars in bail.

The trial judges overseeing the court proceedings, which began Sunday, resigned under mysterious circumstances Wednesday. The investigative judges, who function roughly the way American prosecutors do, announced Friday that they would resign from the case in protest.

“Why is there no fair investigation into the court’s resignation and the truth about the circumstances?” the speaker of the lower house of parliament, Mohammed Saad el-Katatny, said in an address to both chambers. “The People’s Assembly will employ all its means and tools to reveal the truth and hold those responsible for this crime accountable.”

Katatny said parliament would hold a special session March 11 to discuss the case.

The reassigned court case was scheduled to begin Thursday. The 14 Egyptian defendants still in the country are expected to appear in court.