Fatah remains torn by internal divisions a month after it lost control of Gaza to Hamas and some believe Palestinian President Mahmoud Abbas could also lose power in the West Bank, if his faction does not reform.
The power struggle, corruption and lack of leadership since the death of iconic leader Yasser Arafat in 2005 all contributed to the rout by the forces of Islamist group Hamas in Gaza, supporters of moderate Fatah say.
Hamas seized Palestinian Authority buildings in Gaza on June 14, reducing Abbas's authority to the Israeli-occupied West Bank, the larger of the two Palestinian territories.
Some Fatah leaders' homes and offices were ransacked, hundreds fled the enclave and Hamas's armed wing said it had ''executed'' at least one leading Fatah militant.
''One month on, I have not seen any move towards reform within Fatah. This is a major source of concern. There are signs that Fatah has still not woken up,'' said senior Fatah official, Sufian Abu Zaideh, who was forced out of Gaza after Hamas abducted him and threatened his life.
''If things remain unchanged in Fatah, we're heading for a third catastrophe,'' Abu Zaideh said in the West Bank. Before losing control of Gaza, Abbas's movement had already lost a parliamentary election to Hamas 18 months ago, a stunning blow to a party used to unchallenged authority.
If it fails to change now, Fatah might collapse to leave a vacuum the Islamists could fill, Fatah officials, Arab and Western diplomats in the region say.
Responding to the Gaza crisis, Abbas last month declared a state of emergency and dismissed Prime Minister Ismail Haniyeh of Hamas.
But Haniyeh defied the order and Hamas has tightened its control over the Gaza Strip.
Fatah is the anchor of the Palestine Liberation Organisation, but its credibility has suffered in the eyes of many as the old guard of leaders have refused to step down in favour of a younger generation.
The older leaders largely come from the underground movement founded by Arafat in exile in 1965, while younger figures mostly represent a generation that grew up under Israeli occupation.
Abbas is accused by many followers of being distant and weak, without Arafat's personal hold over disparate elements that had held Fatah together.
Many of Fatah's most influential young leaders are either jailed in Israel or were discredited in last month's showdown with Hamas.
No prominent leaders remain in Gaza to challenge Hamas for control of the coastal enclave.
Fatah officials have discussed reforms in recent weeks, but some argue real renewal requires the departure of the old guard, which controls the group's funds.
''Those who contributed to the failure must step down,'' said senior Fatah official Abu Ali Shaheen.
''I believe it is still possible to reform Fatah. But it will take time. We will emerge from under the dust.''
Former US Middle East envoy Dennis Ross sees a need for immediate reforms within Fatah to avoid a complete Hamas takeover of Palestinian politics: ''If Hamas takes over then it becomes a religious conflict.
''Fatah will only remain in charge of the West Bank if it changed,'' he told an Israeli newspaper.
''It has to end the image and reality of its corruption. It has to show it can deliver on a better life for Palestinians and achieve Palestinian national aspirations. If it doesn't, it will lose in the West Bank,'' he said.
In the aftermath of the rout in Gaza, senior Fatah officials have acknowledged that their continued hold on the West Bank, home to 2.5 million people, is partly thanks to Israeli forces.
Israeli Foreign Minister Tzipi Livni, in remarks published on Thursday, said any Israeli withdrawal in the present circumstances would run the risk of seeing the West Bank sink into civil war and repeat what happened in Gaza.
Fatah reformists are proposing new parliamentary and presidential elections -- but they say that could be a big gamble for the faction if it does not change quickly.
''The results of such elections are not guaranteed,'' Fatah official Abu Zaideh said. ''If Fatah fails to reform, it will lose.''
