Two opinion polls published Monday predicted a tight Palestinian presidential race between interim leader Mahmoud Abbas (search) and his jailed challenger, Marwan Barghouti (search), while a third gave Abbas the advantage.

Abbas, a pragmatist who has spoken out against violence, enjoys the tacit support of the international community. A Barghouti victory in the Jan. 9 vote could throw Mideast peace efforts into turmoil.

Abbas, 69, is the candidate of the ruling Fatah (search) movement.

He had been seen as lacking voter appeal, especially among younger Palestinians and hard-liners. However the three polls published Monday indicated a significant increase in backing for Abbas since the nomination. He scored between 35 percent and 40 percent of voter support.

The surveys yielded vastly differing results for Barghouti, a leader of Fatah's restless young guard, who announced his bid at the last minute last week, after initially promising to stay out of the race in order to ensure an orderly transition following Yasser Arafat's (search) Nov. 11 death.

Barghouti, who is serving multiple life terms for his role in deadly shooting attacks on Israelis, drew criticism for his bid, even by allies in Fatah who feared it would split the movement. Barghouti has justified attacks on Israelis in the West Bank and Gaza as legitimate resistance to occupation, but also supports the creation of a Palestinian state living peacefully alongside Israel. Israel has ruled out releasing him from prison.

In a poll by the West Bank's Bir Zeit University, 35 percent said they supported Barghouti, compared with 34 percent for Abbas. A survey by the Palestinian Center for Policy and Survey Research, headed by independent pollster Khalil Shekaki, said Abbas had 40 percent support, compared with 38 percent for Barghouti. Only one survey, by the Palestinian Center for Public Opinion, run by pollster Nabil Kukali, showed support for Abbas of 40 percent, compared with 22 percent for Barghouti.

There are 10 contenders for Palestinian Authority president. All three polls were conducted after Wednesday's deadline for announcing candidacies. In all three surveys, pro-democracy activist Mustafa Barghouti, an independent and a distant relative of Marwan Barghouti, came in third, with scores ranging from 6 percent to 14 percent.

The Bir Zeit poll was conducted among 1,198 respondents, Shekaki's survey was conducted among 1,320 respondents, and Kukali's poll was based on 997 respondents. All had an error margin of 3 percentage points.

The Bir Zeit poll indicated that support for Marwan Barghouti is particularly strong among women, youths, villagers, the poor and the less educated. Abbas scored higher among men, the middle-class, the elderly, the educated and city residents.

Abbas is more popular in Gaza, while Barghouti scored higher in the West Bank. Barghouti also had strong backing among Palestinians who generally support the Islamic militant opposition groups.

The largest of these groups, Hamas, has called for a boycott of the presidential elections, and it was not clear if its supporters would heed the call.

All three surveys indicated that support for Fatah was increasing, while Hamas was losing popularity. During more than four years of Israeli-Palestinian fighting, Hamas had steadily gained support and pulled even with Fatah, which dominated Palestinian politics for decades.

Hamas is not fielding a candidate in the presidential election and asked its supporters not to vote. However, the Islamic militant group says it will participate in legislative and municipal elections, to be held in 2005.

Palestinians last held general elections in 1996.

In Jerusalem, meanwhile, Israeli Prime Minister Ariel Sharon warned rebels in his Likud Party that he was determined to invite the moderate Labor Party into the government, and would not hesitate to call early elections if Likud blocked him.

He said he knew that some Likud legislators want early elections because they think they can topple him.

"I know those who want elections now want them because they think they can bring me down," Sharon said. "That won't happen. I'm not afraid of elections. I intend to run and I intend to win elections."

Sharon, who has lost his majority in parliament, needs Labor to go ahead with a planned withdrawal from the Gaza Strip and four West Bank settlements in 2005. Likud rebels, who oppose a withdrawal, have balked at bringing in Labor.

Likud's Central Committee is to decide later this week. For now, elections are set for November 2006.