RAMALLAH, West Bank – A day after jailed uprising leader Marwan Barghouti shocked his compatriots by announcing he’ll run for president, many Palestinian Arabs denounced him yesterday for endangering unity and a smooth transition of power in the post-Yasser Arafat era.

Barghouti’s last-minute decision to enter the January 9 election roiled what was shaping up to be a rather staid campaign to replace Arafat and created a strong challenge to interim Palestinian Arab leader Mahmoud Abbas.

Analysts say a Barghouti victory could bode ill for peace prospects with Israel.

Mr. Abbas has criticized the violent aspects of the 4-year-old Palestinian Arab uprising and called for new talks with Israel, which has responded warmly.

Barghouti, an uprising leader, is serving five life terms in an Israeli prison for a series of murder convictions. Israel, which has denounced him as a terrorist, said it would not free him even if he won and would almost certainly shun him, as it did Arafat.

Mr. Abbas, 69, is seen as a representative of the old guard of Fatah, which some Palestinian Arabs see as corrupt and condescending. Barghouti, 45, is a leader of the younger generation, with strong grass-roots support.

Palestinian Arab society places high value on unity and consensus. So when Fatah chose Mr. Abbas as its candidate, Barghouti faced intense pressure to stand down. Last week, he announced through intermediaries he would not run and threw his support to Mr. Abbas.

But Barghouti suddenly changed his mind and announced Wednesday he would campaign as an independent, just hours before the registration deadline.

His on-again off-again candidacy, coupled with his defiance of Fatah, shocked, confused, and angered many Palestinian Arabs, including his younger constituency.

Fayza Yousef, 35, from the West Bank city of Ramallah, said she originally planned to vote for Barghouti and respected his decision not to run, but she lost that respect when he changed his mind.

“He seems to me immature, playing games, ‘yes and no.’ I’m not voting for him, and many other people I know were annoyed by that,” she said.

Khamis Namer, a 23-year-old student at Gaza’s al-Azhar University, said he was baffled by Barghouti’s behavior.

“How can a person calling for unity himself break this unity? I think Marwan has made a mistake. Abu Mazen [Mr. Abbas’s nickname] is not an angel, Marwan as well, but in the end we should respect Fatah’s decision,” he said.

Palestinian Arab officials also were clearly annoyed. Some had expressed fears that Barghouti would split the Fatah vote with Mr. Abbas, allowing a third candidate to slip ahead.

“We hope that he will reconsider his position, because the unity of the Fatah and the interest of the Palestinian people is to support the candidacy of Abu Mazen,” Palestinian Arab official Nabil Abu Rdeneh said.

Barghouti, who learned Hebrew while serving time in Israeli jails in the 1980s, advocated a Palestinian state alongside Israel, supported interim peace deals, and had close ties to Israeli peace activists.

But he became a leader of the uprising that broke out in 2000, saying force – including shooting attacks on Israelis – was justified to end Israel’s occupation of the West Bank and Gaza Strip.

He was convicted and sentenced to five life terms in an Israeli prison for his role in the killing of four Israelis and a Greek monk. He denied the charges.

Prime Minister Sharon said yesterday that Barghouti would remain in jail. “He can [campaign] according to the conditions in the prison in which he sits,” Mr. Sharon said.

Efraim Inbar, an Israeli political analyst, denounced Barghouti as a terrorist and said little separated him from Arafat. “There is no difference in what they demand of Israel, the same maximalist demands, and he cannot deliver, just like the other guy,” he said.

Barghouti’s role in the uprising, and his imprisonment, made him one of the most popular Palestinian Arab leaders. But many Palestinian Arabs are now tired of the uprising and see Mr. Abbas as the best chance to end it and ease Israeli restrictions that have crippled their economy.

“The Palestinian people now need a political man like Abu Mazen, because we need a political solution. If we elect Marwan Barghouti, that means there will be no solution and no hope for easing our life,” said Ashraf Abu Arrah, 27, who works in the Palestinian Education Ministry.

Hani Masri, an analyst for the al-Ayyam newspaper, said Barghouti never presented a good reason for changing his mind about running.

“Marwan appears to be struggling for his own interests, only to be released, and that reduces his chances,” he said.

But others said they would vote for Barghouti because of his support for the uprising.

“Marwan is a strong fighter, he is committed to Palestinian rights,” said Ahmed Munir, 20, an accounting student at Beir Zeit University. “If we try Marwan, Marwan might lead us to regain our rights.”