Showing a new knack for popular politicking after decades as a deputy, Mr Abbas called for the structure to be removed, saying there would be no peace until Israel tore it down.
Saying it would never deliver security, Mr Abbas told supporters “If we are to co-exist with the Israelis, this wall must disappear.”
“The Berlin Wall was the last racist wall and it fell. We hope to see this wall fall and that peace and security can take its place”, added the favourite to win the January 9th poll.
His stance drew cheers from thousands at a rally in the town of Qalqilya, 500 meters from the structure.
The citizens of Qalqilya have been totally encircled by a combination of towering slabs of concrete and electronic fencing, ruled illegal by the World Court.
Israel says the barrier, a mix of electronic fences and walls that encroaches on West Bank territory by differing amounts over the 200 km built so far, is a bid to prevent attacks on its territory by Palestinian militants.
Israel points to a sharp fall in recent suicide bombings as proof of its success.
Figures broadcast by army radio Wednesday claim 14 attacks were carried out in Israel during the past 12 months as against 25 in 2003.
But the Palestinians regard the barrier, often jutting deep into their territory, as proof of Israel’s real intent to appropriate land and prejudge the borders of their promised future state.
Thousands of farmers have been separated from fields and the barrier has hampered trade between villages and market towns like Qalqilya, where 40,000 people are ringed by concrete except for one small outlet.
In July, the International Court of Justice ruled parts of the barrier built on the Palestinian side of the internationally recognised border between Israel and the West Bank are illegal.
Israel vowed to ignore the non-binding verdict but has modified its route after rulings from its own supreme court.
Mr Abbas, who is standing for the dominant Fatah faction, repeated vision of an independent state on all the land occupied by Israel since 1967, with east Jerusalem as its capital.
He also paid a visit to the local refugee camp where he met the parents of “martyrs” of the conflict with Israel and with members of Al-Aqsa Martyrs Brigades, an armed offshoot of Fatah.
The PLO chairman, also known as Abu Mazen, was accorded a hero’s welcome in the camp, and was carried briefly on the shoulders of one of the refugees.
But on Wednesday his campaign suffered a minor setback.
The Popular Front for the Liberation of Palestine (PFLP) endorsed the independent candidate, Mustafa Barghuti, who polls show is running a distant second.
The endorsement of the left-wing organisation increases Mr Barghouti’s chances of finishing second in the poll.
The PFLP had boycotted the last Palestinian presidential elections in 1996.