Israel is concerned that the Fatah conference in Bethlehem will end with decisions that can undermine the authority of Palestinian Prime Minister Salaam Fayad, defense officials warned on Tuesday. The conference, the sixth of its kind, opened on Tuesday in Bethlehem and was attended by over 2,000 delegates from across the Arab world who will likely choose a new leadership and platform for the movement. Israel's concern is that the new leadership will not only be more radical but would want to see one of its own - a member of Fatah - as prime minister of the Palestinian Authority, a post currently held by Fayad, a world-renowned economist and leader of the Third Way Party, a small centrist faction that won two seats in the 2006 elections. "Fayad has been instrumental in the recent developments in the West Bank," one senior defense official said. "He has played a key role in Israeli and Palestinian efforts to improve the quality of life in the West Bank, including efforts to revamp the PA security forces." If Fayad is replaced, an Israeli official said, these efforts could be undermined and face setbacks. Meanwhile Tuesday, Hamas gunmen prevented 50 Palestinians who were supposed to cross into Israel from the Gaza Strip for medical treatments from reaching the Erez Crossing. According to Israeli officials, Hamas operatives blocked traffic on the road that leads to the crossing. The Hamas blockade, the officials said, was likely due to suspicions that Fatah officials were pretending to be sick in an effort to sneak out of Gaza and attend the Fatah conference in Bethlehem. Hamas men at the junction ordered those arriving at the crossing to return to the Interior Ministry in Gaza City and have their permits to leave the Strip reissued. Arab MKs participated in the Fatah assembly, and infuriated Jewish MKs with their fiery rhetoric. As one of the most popular speakers at the assembly's opening session, MK Ahmed Tibi (UAL-Ta'al) said the Palestinian state must be free of Jewish settlers and that Israeli Arabs were an inseparable part of the Palestinian people. "We, Arab citizens of Israel, are an inseparable part of the Palestinian people, we are the original residents here, and we will never leave. We own the lands here and are not guests," said the veteran MK. "Whoever came last should leave first," added Tibi, who stressed that merely freezing building in settlements was insufficient and that Israel must "disassemble them." He claimed that peace could not be achieved with settlements or settlers. To a roar of applause from the delegates in attendance, Tibi called on settlers to "get out of Palestinian lands, get out of our souls, get out!" "My suggestion for Tibi is that he get out of my soul," responded Diaspora Affairs Minister Yuli Edelstein (Likud). "I'm sick and tired of people who deliver speeches about being an integral part of the Palestinian people but choose to sit in the Israeli Knesset and enjoy all of the benefits of the Israeli democracy." Improvement of Government Services Minister Michael Eitan accused Tibi of worsening the situation in the Middle East. "Whoever wants to kick Jews out because they oppose their living next to Arabs brings upon himself similar statements by Jews addressed toward Arabs," said Eitan. "Expressions of this sort are a stumbling block to peace and bring about dangerous extremism that does not aid in healing the rifts between the nations, and certainly does not help achieve peace in our region." Tibi was not the only representative of the Israeli Arab parties at the convention. Hadash chairman Muhammad Barakei and UAL-Ta'al MK Taleb a-Sanaa both attended, alongside former wanted terrorist Zakariya Zubeidi, Fatah strongman Jibril Rajoub and others. Tuesday's rhetoric at the Fatah convention did not elicit any direct response from the Prime Minister's Office. Rather, Prime Minister Binyamin Netanyahu's spokesman Mark Regev said Israel "remained committed to moving forward with peace with our Palestinian neighbors, and that the formula for such peace is clear: Palestinian recognition of the legitimacy of Israel as the homeland of the Jewish people, and a demilitarized Palestinian state." Israel is ready to immediately start political negotiations with the Palestinian leadership "without any preconditions," he said. "The problems are only going to be solved around the negotiating table." Defense Minister Ehud Barak said that Israel was not interfering with the Fatah conference and had facilitated the participation of as many delegates as possible. "We don't get involved in internal Palestinian issues," he said, stressing the importance of the conference representing as wide a range of Palestinian views as possible. "We shouldn't ignore it, but neither should we make too much of it," added Barak. "The test will come after the conference. We will see what the leadership brings to the negotiating table - that's what matters." But Edelstein had a different perspective. "I think that our foremost challenge is to make sure that everyone around the world knows about the things said at the conference," said the minister. "It is especially important for those who ask why we're so stubborn and why we 'don't just take a couple of steps to make peace possible' to know that even for so-called moderate leaders of the PLO, violence against Israel is a strategy, that Hamas is being criticized for not letting a couple of PLO functionaries out of Gaza and not for its terror acts, and that the 'right of return' inside Israel is [an Arab] precondition for any peace agreements." Meanwhile, MK Michael Ben-Ari (National Union) fired off a letter to Attorney-General Menahem Mazuz, calling on him to arrest "Fatah terrorists," including Zubeidi, on their way home from the conference. Ben-Ari wrote that no official had the right to allow free movement for terrorists with blood on their hands, especially without any sort of organized process. He added that in light of the "militant statements" from conference participants, security forces should arrest the Fatah activists at checkpoints as they traveled home - and threatened to appeal to the Supreme Court should Mazuz fail to respond to his missive.