Mahmoud Abbas, the Palestinian president, has said he will not talk with any group that fails to recognise the legitimacy of the Palestine Liberation Organisation (PLO) after Hamas called for it to be sidelined.
"We say this with utmost clarity - no dialogue with whoever rejects the Palestine Liberation Organisation," Abbas said as he visited Palestinian victims of the Israeli assault on Gaza in a Cairo hospital.
Abbas's comments in Cairo came ahead of his planned meeting on Monday with Hosni Mubarak, the Egyptian president, for talks set to focus on Palestinian unity and cementing a shaky ceasefire after Israel's war on Gaza, reported Aljazeera.
He also directly criticised Hamas, saying it had put the lives and aspirations of Palestinians at risk by promoting conflict with Israel.
"They ... have taken risks with the blood of Palestinians, with their fate, and dreams and aspirations for an independent Palestinian state," Abbas said.
A delegation from Hamas, which has controlled the Gaza Strip after pushing out security forces loyal to Abbas, was also expected to meet Egyptian mediators in Cairo.
'Dreams and aspirations'
Khaled Meshaal, the exiled Hamas political leader, said earlier in the week that the PLO had become obsolete and called for "a new, national authority".
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His proposal was echoed on Friday by Khalil al-Hayya, a senior Hamas political leader, who said it was "high time the Palestinian people have a new leadership".
Meshaal's comments have not been supported by all Hamas members and other Palestinian factions, many of whom have said that the PLO should be reformed rather than replaced.
Hamas is not a member of the Palestinian umbrella group which Egypt founded in 1964 and which Fatah took over in 1968.
"They ... have taken risks with the blood of Palestinians, with their fate, and dreams and aspirations for an independent Palestinian state," Abbas said.
'No dialogue'
Ahmed Yousef, an adviser to Ismail Haniya, the head of the Hamas government in Gaza, told Al Jazeera that Fatah was the real obstacle to Palestinian unity.
He said Hamas has urged Abbas repeatedly to reform and restructure the PLO to make it more inclusive, but without success.
Hamas officials are travelling to Cairo to hold talks with Egyptian authorities on extending the ceasefire between the group and Israel.
The war on Gaza - dubbed Operation Cast Lead by the Israelis - ended after the Israeli government declared a unilateral ceasefire.
Hamas declared their own halt to the fighting the following day but their has been no agreement between the two sides.
'Positive direction'
Yousef said that Hamas was waiting for a response from Israel to a proposed formal truce put forward by Egypt.
Meshaal has criticised the PLO, saying it has become obsolete [File: AFP]
"We can speak with details about the truce after our delegation examines the Israeli response," he said.
"But for now, things are moving in a positive direction."
Hamas wants an end to the Israeli blockade of the territory, while Israel has demanded an end to Palestinian rocket fire and moves to halt weapons smuggling in the Gaza Strip.
Israel refuses to negotiate directly with Hamas and, as the country approaches parliamentary elections on February 10, cabinet members reiterated that it would not do any direct deals with Hamas.
"A deal with Hamas would give it legitimacy and anyone working towards one with Egypt must understand that," Tzipi Livni, the foreign minister and a candidate for prime minister, told a cabinet meeting.
"I support agreements against Hamas and not with Hamas. We must not hold negotiations on a ceasefire."
Since the separate ceasefires were called there have been sporadic rocket attacks into southern Israel and Israeli air raids on the Gaza Strip.