From deep within an Israeli prison, Palestinian uprising leader Marwan Barghouti has once again thrust himself to the forefront of the Israeli-Palestinian conflict.

By organizing a mass hunger strike by hundreds of Palestinian prisoners, Barghouti has solidified his standing as a likely successor to President Mahmoud Abbas. He also has proven to Israel that, despite serving multiple life sentences, he cannot be ignored as the country marks 50 years of control over the Palestinian territories.

Barghouti is the most prominent of the thousands of Palestinians held in Israeli prisons, and even after 15 years behind bars, he continues to cast a long shadow over the region.

While viewed by Israel as an arch terrorist, he is seen by Palestinians as a national hero, often drawing comparisons to the late South African President Nelson Mandela. He has called the new hunger strike the "long walk to freedom," the title of Mandela's autobiography about life in prison during the apartheid era.

"Marwan is the best candidate to inspire and lead the new generation from behind bars, just as Mandela did," said Qadura Fares, a Barghouti supporter and leader of the Palestinian prisoners' association.

Palestinian officials say Israel is holding some 6,500 "security prisoners" -- people jailed for charges ranging from stone-throwing and membership in groups outlawed by Israel, to attacks that wounded or killed Israelis. Several hundred are being detained without charges.

Barghouti was arrested in 2002 during the violent Palestinian uprising and convicted on multiple counts of murder. Israel charged him with directing suicide bombings against its citizens, and he was sentenced to five life terms. Barghouti did not offer a defense, refusing to recognize the court's authority.

As many as 1,500 prisoners are believed to have joined the strike. Their immediate demands included better conditions, more contact with relatives, and an end to Israel's practice of detentions without trial.

But the strike's significance runs far deeper, with long-ranging implications in the brewing struggle to succeed the 82-year-old Abbas and efforts to end a bitter 10-year rift between Abbas' Fatah movement and the rival Hamas militant group.

In an op-ed published in The New York Times, Barghouti wrote that Israeli prisons have become the "cradle of a lasting movement for Palestinian self-determination."

Over the years, polls have indicated that Barghouti is the most popular choice among Palestinians to succeed Abbas, who has refused to groom a political heir.

He also is seen as the only figure in Abbas' Fatah movement who also enjoys support from Hamas, which seized control of the Gaza Strip from Abbas' forces a decade ago. The ongoing rift is a major impediment to Abbas' goal of establishing a Palestinian state in both territories.

Barghouti appears intent on becoming the next Palestinian president, and some believe that Israel will be forced to release him because he is such a unifying figure to the Palestinians.  Over the years, Israel has released a number of top security inmates in prisoner swaps and other agreements with the Palestinians.

With peace efforts frozen, any potential release seems far off at best. But Barghouti is busy preparing for the future by using the hunger strike to shore up his standing.

In December, he was the top vote getter at a Fatah leadership contest, but was nonetheless denied a senior position in the movement, in what many saw as an effort by Abbas to sideline him.

"This strike is bringing him back again to the forefront of Palestinian politics," said Akram Atallah, a columnist for the pro-Fatah al-Ayyam newspaper.

"Barghouti is preparing himself for the post 82-year-old President Abbas era," he said.

Israel's prison service said Barghouti has no special status and is treated like any other prisoner. But the day after the strike began, Israel announced that Barghouti had been transferred to a new prison and placed in solitary confinement.

Prime Minister Benjamin Netanyahu condemned the New York Times for describing "arch-terrorist Marwan Barghouti as a `parliamentarian and leader"' in his op-ed piece. Under Israeli pressure, the paper amended his article with a note describing the crimes for which he was convicted, while also noting his refusal to recognize the Israeli court's legitimacy.

For now, Israel is taking a tough line, vowing not to negotiate with the hunger strikers.

Michael Oren, Israel's deputy minister for public diplomacy, called Barghouti a "convicted mass murderer of Israelis."

Oren said Barghouti "should remain behind bars and serve out those sentences until the last day of his life."

He said the hunger strike "has nothing to do with the state of Israel," and instead was connected to Fatah infighting. "I think Israel should sit quietly. If these people want to go hungry, that is their decision," he said.

But as the strike drags on, it may become harder to ignore. The strike has generated widespread support among the Palestinian public, and if anything happens to Barghouti it could ignite unrest.

Barghouti's wife, Fadwa, said she fears for her husband's life and the health of all prisoners. "This is a matter of life or death. A hunger strike is not easy," she said.

Elias Sabagh, Barghouti's lawyer, said he has received permission to visit his client on Sunday for the first time since the strike began. He said Barghouti is mentally tough and has spent time in solitary confinement. He described Barghouti as a voracious reader who enjoys books in English, Arabic and Hebrew, and closely follows the political situation.

Alon Eviatar, a former high-ranking officer in COGAT, the Israeli defense body responsible for Palestinian civilian affairs, said that as the hunger strike drags on, both sides will be pushed to compromise.

Barghouti "views himself not just as the Fatah leader but leader of all the Palestinians. He will succeed if he gets better conditions for all prisoners," he said.