CAIRO — An ultraconservative Islamist adviser to Egypt's President Mohammed Morsi has resigned in solidarity with a fellow aide who was fired amid allegations of abusing his office.

The Monday resignation of Bassam Zarka, who is a member of the Salafi Al-Nour party, is the latest sign of tension between Morsi's Muslim Brotherhood and its Islamist ally months before parliamentary elections.

Zarka dramatically announced his resignation at a live press conference during which his Al-Nour colleague and former presidential adviser, Khaled Alam Eldin, broke down in tears as he denied the allegations that he had abused his office.

Eldin demanded an apology from Morsi for firing him. The presidency has refused.