More than 300 Palestinians belonging to Yasser Arafat's Fatah organisation have announced their resignations.
Arafat faces complaints about bad leadership within his movement
They are protesting about alleged corruption and divisions within the movement and a failure to respond to calls for reform.
The former members sent a letter to the Fatah leadership complaining about a lack of direction in how the party is handling the conflict with Israel.
The members said their decision to resign was irrevocable even though it might cost them their jobs.
The ex-Fatah members were from the party's lower ranks and none held prominent positions in the movement.
But one senior official in Ramallah, Hussein al-Sheikh, described the resignation statement as a "warning bell".
"To preserve the movement's unity and cohesion and to maintain its leadership of the Palestinian national action and struggle, serious measures must be taken to
effect internal changes in the movement, " Mr Sheikh told the Arabic satellite TV channel Al-Jazeera.
"We should not ignore this wide schism between the movement's base and its leadership bodies."
There is a history of friction between the younger members of the Fatah movement and the old guard brought back from exile after interim peace agreements in the early 1990s to run the newly-formed Palestinian Authority.
Failure to hold elections for the party's governing bodies are at the heart of the dispute.
Party procedure calls for elections every five years, but none have taken place since 1989.