Palestinian Authority President Mahmoud Abbas said on Sunday that he will not hold reconciliation talks with the rival Hamas group unless it accepts his authority, lowering chances the two sides will work out their differences any time soon. Egypt has been pushing for reconciliation between the rival Palestinian factions, which could be a key step in opening the Gaza Strip's borders and producing a long-term truce between Hamas and Israel. But the exiled leader of Hamas, Khaled Mashaal, directly challenged the PA president's power Wednesday, saying the group of Palestinian factions led by Abbas - known as the PLO - "in its current state is no authority." "It expresses a state of impotence, abuse and a tool to deepen divisions," Mashaal told a rally organized in the Qatari capital of Doha. The PLO is the internationally recognized representative of the Palestinians and is dominated by Abbas' Fatah faction. Hamas has refused to join the PLO, and Mashaal said Wednesday he was working to create an alternative structure to include all Palestinians. "I say clearly there will be no dialogue with those who reject the PLO," Abbas said at a Palestinian gathering in Cairo. "They (Hamas) must recognize in no hidden terms and without vagueness that the PLO is the sole and legitimate representative of the Palestinian people, then there can be dialogue." He called the attempt to replace the PLO with a new organization a "destructive" project. Abbas spokesman Nabil Abu Redeineh said Hamas officials "have to recognize the PLO as the sole representative, with all its commitments and its obligations." That includes committing to Israeli-Palestinian peace and a two-state solution, which Hamas has rejected. The rivalry between the two sides deepened after Hamas's violent takeover of Gaza from Fatah in 2007. Fawzi Barhoum, a Hamas spokesman in Gaza, said Abbas' statement "aborts all Palestinian, Egyptian and Arab efforts aiming to make a Palestinian national dialogue a success." "We hold (Abbas) totally responsible for the repercussions of these statements, which deepen the internal rift," said Barhoum in a statement e-mailed to reporters. Hamas and Fatah have disagreed about power sharing within the Palestinian territories and relations with Israel. But Abbas has not previously demanded that Hamas recognize the PLO as the legitimate representative of the Palestinian people as a precondition for reconciliation talks. The new demand could make it more difficult for Egypt to broker a deal between the two sides. Hamas officials are expected to meet with Egyptian mediators Monday, while Abbas and Saudi Foreign Minister Saud al-Faisal are scheduled to hold talks with Egyptian President Hosni Mubarak. Egypt has been trying to mediate a long-term truce between Hamas and Israel to replace a fragile cease-fire that halted the Jewish state's three-week offensive against Gaza about two weeks ago. Egyptian officials have expressed hope they could forge a long-term truce by the end of this week and reconciliation between Hamas and Fatah by the end of February. But negotiations over the truce have snagged on the issue of Gaza's borders. Hamas has said it will only agree to a long-term cease-fire if Gaza's crossings are opened. But Israel does not want Hamas to have control over its borders, worried that the group will use the opportunity to smuggle additional arms into Gaza. Egypt has proposed opening the crossings on the basis of a 2005 agreement brokered by the US that puts Abbas' people in control of the borders, with European monitors deployed to prevent smuggling. But Fatah has no control in Gaza, and any such deal would require some form of reconciliation with Hamas. But Hamas has said negotiations over Israel's Gaza offensive should not be tied to the issue of Palestinian reconciliation. Abbas on Sunday accused Hamas of stalling in its response to Egypt's mediation proposal and said the group has reduced the Palestinian cause to an "issue of crossings."