One of Palestinian leader Yasser Arafat's top security advisors resigned Monday citing the slow pace of internal reform.
Palestinian National Security Advisor Mohammad Dahlan's decision to quit his post is effectively a protest against Mr. Arafat's leadership.
Mr. Arafat is under international pressure at home and abroad to make sweeping changes to his administration, which many ordinary Palestinians believe is riddled with mismanagement and corruption.
Mr. Dahlan's resignation letter says he is opposed to the long delays in implementing security and administrative reforms.
His decision to quit also follows a week of political turmoil and violence in the Gaza Strip.
Just days before he decided to leave his post, he said that the Palestinian Authority had reached a critical juncture because of challenges from Hamas, the Islamic Resistance Movement.
In an interview with the Boston Globe newspaper, he said Hamas' killing of a high-ranking police commander in the Gaza Strip last week was a test of the Palestinian Authority's ability to stay in power.
"It's a life-and-death question for us," said Mr. Dahlan. In his words, "Hamas did this to test Fatah [Mr. Arafat's faction] and to say there is no Authority any longer. It is an open challenge to the Palestinian Authority."
Mr. Dahlan demanded that Hamas hand over those suspected of killing the police commander or risk the Palestinian security forces taking matters in their own hands.
His tough approach appeared to be undermined by other Palestinian officials such as Nabil Shaath, who said Monday that Fatah and Hamas would enter into talks soon in one of the Arab Gulf States.
Meanwhile, in the Gaza Strip Monday thousands of Fatah supporters marched through the streets calling for Palestinian unity.
The rally was meant to be a show of strength amid its feud with Hamas. Following the murder of the police commander, Palestinian security forces opened fire on demonstrators last week, killing several Hamas activists.