The submission of a united candidate list on Wednesday, headed by jailed intifada leader Marwan al-Barghuti, marked Fatah's attempt to overcome deep divisions that saw the faction initially register two rival lists for the 25 January polls.
Only after lengthy talks did the two strands of the party agree to merge the two line-ups, fearful that they would otherwise see their decade-long grip of power slip away at the expense of Islamic group Hamas, contesting its first legislative polls.
Fatah won legal approval earlier this week for the registration process to be reopened for a six-hour period on Wednesday.
Muhammad Dahlan, outgoing civil affairs minister, said at the election commission's Ram Allah headquarters that "The Future list is no more and the movement has a single list".
Dahlan's name had been on the alternative list of candidates which had been known as the Future, but he said he was confident that a united Fatah would be victorious.
"I urge all my brothers in Fatah to cast their votes and fight for every vote in their towns and villages to ensure victory for the movement," said Dahlan.
"The Future list agreed that Fatah should have a single list to ensure the movement's unity and its victory in the 25 January elections"
Security adviser to Mahmoud Abbas
He said a victory for Hamas would be "a long road to perdition and obscurity".
Palestinian leader Mahmoud Abbas's security adviser Jibril Rajub, whose name was also on the list of Future candidates, said the fused line-up was designed to maximise its own electoral prospects.
"The Future list agreed that Fatah should have a single list to ensure the movement's unity and its victory in the 25 January elections," Rajub said.
Blamed for years of corruption within the Palestinian Authority, Fatah has been weakened by a credible threat from Hamas which swept to victory at a series of municipal elections in Gaza and West Bank earlier this year.
The Fatah-dominated Palestinian Authority has also proved largely incapable of clamping down on pervasive insecurity in the territories.
Dozens of masked armed men from the Al-Aqsa Martyrs Brigades, a radical Fatah offshoot, earlier traded fire with police at an electoral office in Gaza City and dozens more occupied and surrounded registration offices elsewhere in Gaza.
Electoral offices were later declared re-open after the armed men ended their siege that left at least one policeman wounded, said a senior electoral commission source.
"We have reopened all the offices," the source said.
Al-Aqsa Martyrs Brigades fighters
raided several election offices
"Gunmen have ended all sieges. There were clashes in Gaza City that left one policeman wounded. He is being treated in hospital."
Al-Aqsa activists stormed electoral offices in the southern town of Khan Yunis and Deir el-Balah in central Gaza, as well as surrounding another in the impoverished southern border town of Rafah.
The armed men told reporters that they had stormed and surrounded the buildings because they wanted to be represented on the Fatah candidate list.