An Egyptian administrative court has suspended general elections that were scheduled to begin next month.
It said the law covering the polls needed to be reviewed by the Supreme Court to determine whether it conformed to the constitution.
President Mohammed Morsi had said the polls would begin on 22 April, taking place in four stages over two months.
The elections have been boycotted by the main opposition, amid continuing street protests.
The National Salvation Front (NSF) has said the electoral law favours Mr Morsi’s Islamist allies – a claim denied by the president.
The NSF has also expressed concerns that the election will not be free and fair.
Egypt remains sharply divided between Islamists and their liberal and secular opponents.
More than 70 people were killed in violence between security forces and protesters since February, following the second anniversary of the revolution that ousted President Hosni Mubarak.
