“This is one of the most significant political developments in Fatah since Abbas became president in 2005,” said Mr. al-Omari. “Barghouti and Kidwa are a combination that can’t be easily dismissed by the Fatah leadership. They have a very deep reservoir of legitimacy in the party and they represent a major challenge to Abbas’s hold on power in it.”
Mr. Barghouti ran for president of the Palestinian Authority in 2004, before withdrawing and supporting Mr. Abbas. He had been a leader of the Palestinian uprisings in late 1980s and early 2000s, and was convicted in 2004 for involvement in the killings of five Israelis.
He was sentenced to five life terms and campaigned for office from his jail cell.
Fatah’s supporters will now be forced to choose among three Fatah-linked factions — the official party, the Barghouti-al-Kidwa alliance, and a third splinter group led by an exiled former security chief, Muhammad Dahlan.
Members of Mr. Barghouti’s alliance said they had created the new faction to revitalize Palestinian politics, which has increasingly become a one-man show centered around Mr. Abbas, who has ruled by decree for more than a decade.
“The Palestinian political system can no longer only be reformed,” said Hani al-Masri, a member of the new alliance, at a news briefing on Wednesday night. “It needs deep change.”
A Fatah official dismissed the group as “turncoats.”
“Even with our prophet Mohammed, there were turncoats,” said Jibril Rajoub, the secretary-general of the Fatah Central Committee, at a separate press briefing outside in Ramallah, West Bank. “Fatah is strong and sticking together.”
Mr. Abbas has canceled elections in the past, and some believe he may seek to do so again in the coming weeks.