The new head of the Palestinian Fatah movement has threatened to expel popular leader Marwan Barghouti unless he withdraws from the Palestinian presidential race.
Barghouti is seen as the only serious challenger to the official Fatah candidate, former prime minister Mahmoud Abbas.
Fatah chief Faruq Qaddumi says any member who goes against the group's decisions should resign and have his membership cancelled.
The 45-year-old Barghouti is currently serving five life terms in an Israeli prison for planning suicide attacks.
Mr. Barghouti, who has denied involvement in the attacks, filed papers for the January 9th presidential race last Wednesday.
The winner of the race will succeed the late Yasser Arafat and lead the Palestinians as world powers try to revive the Middle East peace process.
Some information for this story provided by AFP and Reuters.