Palestinians from across the political spectrum warned Wednesday that Israel's decision to target Kassam cells in the Gaza Strip will lead to the total collapse of the current cease-fire. Meanwhile, Palestinian Authority Chairman Mahmoud Abbas proposed holding "backdoor" negotiations with Israel over final-status issues such as the status of Jerusalem, the future borders of a Palestinian state and the "right of return" for Palestinian refugees. Abbas made the proposal after meeting in Cairo with Egyptian President Hosni Mubarak. "Some time ago we proposed the idea of backdoor talks with Israel with the participation of one or all members of the Quartet to discuss all the issues of the final status," Abbas said. He had proposed backdoor negotiations to Prime Minister Ehud Olmert during their meeting last Saturday, he said, adding that Olmert had no immediate objection and promised to consider the proposal. Abbas said he planned to discuss the idea with US Secretary of State Condoleezza Rice during her visit to the region in mid-January. "There will be a need to revive this idea and discuss it seriously when Rice comes to the Middle East," he said. "These are not secret negotiations, therefore, they would help more than they would harm," Abbas said. "The Americans are also not opposed to the idea. We're not talking about secret negotiations, but an undeclared channel." Asked about the case of captured IDF Cpl. Gilad Shalit, Abbas said Olmert made it clear to him that the release of Palestinian prisoners from Israeli jails was dependent on the fate of the soldier. However, he pointed out, Olmert promised to release a number of prisoners as a goodwill gesture on the eve of the Muslim feast of Eid al-Adha, which begins Saturday. "We had a serious discussion with Olmert on the issue of the prisoners," Abbas said. "We are very keen to have all our prisoners freed." Reiterating his determination to call early presidential and legislative elections, Abbas nevertheless stressed that he would keep the door open for the formation of a unity government with Hamas. "The main purpose behind the establishment of a unity government is to end financial sanctions imposed by the international community on our people," he said. Abbas dismissed allegations by his political rivals that he was trying to topple a democratically elected government. "The same people who voted for Hamas also voted for me as president and this is democracy," he explained. "If it hadn't been for the international siege, the [Hamas] government could stay in power for four years and another four years afterwards. But the reality is that Hamas has failed to tackle the problem of the sanctions." Palestinian officials and activists expressed fear that Israel's decision to resume targeted attacks against Kassam squads in Gaza would put an end to the current cease-fire. Ghazi Hamad, spokesman for the Hamas-led government, accused Israel of exploiting the rocket attacks to "launch a massive attack on the Gaza Strip." Hamad urged all Palestinian groups to abide by the cease-fire agreement so as not to provide Israel with an excuse to violate it. "The cease-fire is in the interest of the Palestinian people and that's why we must honor it," he said. Abu Ahmed, a spokesman for the Al-Quds Brigades, the armed wing of Islamic Jihad, said his group would continue to fire rockets at Israel as long as the cease-fire was not extended to the West Bank. "Israel is continuing to perpetrate daily massacres against our people in the West Bank," he claimed. "We have the right to respond to these attacks. In the next few days we will increase our rocket attacks on Israel." Fatah's armed wing, the Aksa Martyrs' Brigades, also threatened to resume terror attacks if Israel launches attacks on Palestinians who fire rockets at Israeli cities. "Israel's threats will destroy the cease-fire," the group said in a statement issued in Gaza City. PLO executive committee member Yasser Abed Rabbo, who also serves as an advisor to Abbas, warned that the Israeli decision would lead to the breakdown of the cease-fire. He described the decision to target Kassam launchers as a "breach" of the cease-fire agreement.