Some 1,400 members of Fatah were gathering in Ramallah for the five-day conference, where delegates are to hold elections for the party's two main decision-making bodies. In a first step, the delegates unanimously re-elected Abbas as the party leader for a new five-year term. Party official Salim Zanoun asked the hall to vote for Abbas, and participants all stood up and warmly cheered. A smiling Abbas then hugged Zanoun.
While the elections are expected to bring some new faces into the leadership structure, the conference's main purpose appears to be aimed at blocking the return of Abbas' exiled rival, Mohammed Dahlan.
"The Fatah conference is the conference of the independent Palestinian decision, the conference of building and liberation, and national unity," Abbas said. Late Tuesday, Abbas postponed a planned speech to the conference. Officials said he would instead address the gathering on Wednesday.
Dahlan, who was forced to leave the West Bank six years ago after accusing Abbas' sons of corruption, now lives in the United Arab Emirates. He has forged close ties with the leaders of the UAE, Egypt, Saudi Arabia and Jordan.
In recent months, these countries, known as the Arab Quartet, have pressured Abbas to allow Dahlan to return to a leadership position. Abbas, accusing his Arab allies of meddling in his affairs, instead decided to schedule the Fatah elections, while blocking Dahlan and his close allies from participating.
Abbas' supporters rejected criticism that he was focused on Dahlan. They say that the conference, two years behind schedule, had to be held to revive the movement.
Fatah has dominated Palestinian politics since its founding five decades ago. But Abbas has seen his popularity plummet due to years of failed peace efforts with Israel, a stagnant West Bank economy and his inability to reconcile with the rival Hamas movement, which seized control of the Gaza Strip from his forces nearly a decade ago. Abbas now only governs autonomous areas of the West Bank.
In addition, the election of Donald Trump has given the Palestinians little room for optimism. Although the US president-elect has not yet laid out a Mideast policy, many of his advisers are known for hard-line positions in favor of Israel.
"This congress is taking place in a crucial moment in the history of the Palestinian people. We have to discuss our aspirations, our concerns, and challenges," said Jibril Rajoub, a senior Fatah leader and Abbas loyalist.
"We have to build a strategy, consolidating the movement, and achieving national unity," he said, adding: "Dahlan is past. He has no place in the movement."
Abbas was set to address the conference on Tuesday evening. Participants were coming from the West Bank, Gaza Strip, as well as diaspora communities scattered across the Arab world and in the West. The convention is to conclude with elections for 18 spots in the Central Committee, the top decision making body, and 80 members of the movement's parliament, the Revolutionary Council.
Participants reported fierce lobbying in the fight for seats on the two prestigious bodies. The struggle will include attempts by some younger activists to land seats in what are often seen as stodgy bodies dominated by men in their 70s and 80s.
Abbas himself is running unopposed as leader of the movement, and none of his key policies toward Israel are expected to change. Abbas, who succeeded the late Yasser Arafat in 2005, seeks the establishment of an independent Palestinian state in the West Bank, Gaza Strip and east Jerusalem—territories captured by Israel in the 1967 Six Day War.
Many members have accused Abbas of orchestrating the convention to consolidate his grip on the movement.
"The convention is meant to exclude all critic voices in the movement," said Jamal Jahjouh, Fatah's leader in the Qalandia refugee camp in the West Bank.
He said Fatah leaders had excluded key activists from this week's convention and replaced them with Abbas loyalists. He said members of the movement in his camp would protest Tuesday to voice their opposition to Abbas and his convention.
Dahlan was expected to remotely deliver a speech to the convention on Tuesday. His supporters say they plan to hold an alternative convention with 2,000 members in Egypt in the near future to voice their criticism of Abbas and opposition to his policies.
This week's convention is to be followed by a long-overdue meeting of the Palestinian National Council, the parliament of the umbrella Palestine Liberation Organization. The PNC is to elect the top PLO leadership.
Fatah dominates the PLO, but many smaller factions also belong. In a gesture of unity, Fatah invited the rival Hamas and Islamic Jihad militant groups to attend this week's conference as observers. Neither group belongs to the PLO but their membership is seen as crucial to restoring Palestinian unity.
Abbas is scheduled to address the gathering this evening.