Egypt's parliamentary poll looks set to be delayed after a court ruled part of an election law was unconstitutional and the main election committee said it was working on a new timetable for the long-awaited vote.
President Abdel Fattah al-Sisi directed his government to amend the law within one month.
The first phase of the poll is due to start on March 22. The election is the final step in a political roadmap the army announced in July 2013.
Another court ruling later this month will definitively decide whether or not the elections will be delayed.
The latest development highlights Egypt's rocky path towards democracy since the ousting of Islamist President Mohamed Morsi in 2013 by the army after mass protests against the rule of Egypt's first democratically elected leader.
Egypt has been without a parliament since June 2012 when a court dissolved the democratically elected main chamber, reversing a major accomplishment of the 2011 uprising that toppled autocrat Hosni Mubarak.
"The committee will prepare a new timetable for (election) measures after the legislative amendments are issued," the Supreme Election Committee said.
Earlier, the Supreme Constitutional Court said an article in a law defining electoral districts was unconstitutional.
Zaid al-Ali, a senior adviser with intergovernmental organisation International IDEA, said there was "little question" the elections would be delayed.
Legislative drafters need time to understand the ruling, prepare a new version of the law, allow time for review and for any new legal challenges before the election.
Egyptian leaders say the election shows their commitment to democracy. Critics say Sisi, who as army chief toppled Morsi, has undermined freedoms gained after the uprising that ended Mubarak's 30-year rule.
In the absence of parliament, Sisi has wielded legislative authority to introduce economic reforms that have impressed investors, while also curtailing political freedoms.
The People's Assembly is made up of 567 seats, with 420 elected as individuals and 120 through winner-takes-all lists with quotas for women, Christians and youth. The remaining seats are appointed by the president.
Several opposition political parties had announced they would boycott the election. Some say the emphasis on individuals was a throwback to Mubarak-era politics, which often favoured candidates with wealth and family connections.
Egypt is trying to burnish its image in the run-up to an investors' summit in mid-March which the government sees as playing a key role in turning around a battered economy.
Egyptian investors are monitoring political violence which has seen an uptick since Morsi's ouster in mid-2013.
Security sources said at least two people were killed and six others wounded late on Sunday when a bomb exploded in the southern city of Aswan.