Abd al-Sattar Qasim, 56, accused local media and the international community of unfairly favouring PLO chairman and overwhelming frontrunner Mahmud Abbas in his letter of withdrawal to the central elections commission.
"The local media and Arab bias towards the candidate of the Palestinian Authority [Abbas] is obviously an attempt to influence public opinion to the detriment of the other candidates," he said on Monday.
Qasim accused various countries and heads of state of interfering in the election in order to ensure victory for Abbas, citing both the United States and Egyptian President Husni Mubarak.
He also expressed concern over the fairness of the upcoming elections given the restrictions on movement in the occupied territories and the short electoral campaign.
Qasim, a professor of political science at Al-Najah University in Nablus, has been a vocal critic of the Palestinian Authority, spending a total of eight months in prison on three separate occasions for attacks on the late leader Yasir Arafat.
He was wounded by gunmen in a 1995 shooting that was thought to have been carried out by the security services.
The withdrawal of Qasim, who was running as an independent, means that only seven of the 10 candidates who submitted their names when nominations closed at the beginning of the month are still in the running for the 9 January vote.
Abbas, who is the candidate of the dominant Fatah faction, became virtually assured of victory on Sunday after jailed intifada leader Marwan al-Barghuthi also dropped out of the race.
"The local media and Arab bias towards the candidate of the Palestinian Authority [Abbas] is obviously an attempt to influence public opinion to the detriment of the other candidates"
Abd al-Sattar Qasim,
The acting parliament speaker, Hasan Khraisha, also renounced his candidacy last week.
Both Hamas and Islamic Jihad, the two most popular resistance groups in Palestine, are boycotting the elections because they oppose the Oslo peace process which created the Palestinian Authority.