CAIRO (Agencies) - Opposition groups demanding the resignation of President Hosni Mubarak failed to agree a common stance before negotiations with Vice President Omar Suleiman to pull Egypt out of its worst crisis in 30 years. State television said Suleiman began meetings with prominent independent and mainstream opposition figures on Saturday to go through the options, which centre on how to ensure free and fair presidential elections while sticking to the constitution. It did not name the groups he met. The proposal being promoted by a group of Egyptians calling itself the 'The Council of Wise Men involves Suleiman assuming presidential powers for an interim period pending elections. But some opposition figures argue that would mean the next presidential election would be held under the same unfair conditions as in previous years. They want to first form a new parliament to change the constitution to pave the way for a presidential vote that is democratic. A popular uprising has gripped Egypt since Jan 25, with protesters camping out in central Cairo demanding the departure of Mubarak, even after the president on Tuesday announced he would not seek re-election in September. Egypt, the Arab worlds most populous and influential country, faces the danger of a power vacuum unless some sort of agreement on a transitional government is reached. With the negotiations under way, state television announced that the leadership of the ruling National Democratic Party, including Mubaraks son Gamal, had resigned. The resignations were quickly dismissed by the opposition as a ruse. The Wise Men proposal is based on article 139 of the constitution that would allow Mubarak to hand executive powers to his deputy while staying on as figurehead until September, Diaa Rashwan, an expert at the al-Ahram Centre for Political and Strategic Studies and one of the Wise Men, told Reuters. Handing power to Suleiman offers a potential compromise between protesters demands for Mubarak to leave office immediately and his stated decision to stay on until the end of his term in September. Rashwan said all opposition factions and forces, including the influential Muslim Brotherhood, were invited to Saturdays talks but they were divided over some issues, with some unwilling to let Mubarak stay on even in a symbolic capacity. Consultations are continuing to find an end to this crisis, he added. The main opposition groups comprise the Brotherhood, the National Coalition for Change led by Nobel peace laureate and former U.N. nuclear watchdog head Mohamed ElBaradei, the Kefaya (Enough) group and youth represented by the April Sixth Movement, the liberal Wafd party and the leftist Tagammu party. Even if they all agree on the proposal, article 82 of the constitution could present a legal complication. It says that while the president is able to delegate powers to a deputy, that person is not allowed to request constitutional amendments or dissolve the parliament or local shura councils. If that article holds, it would be impossible for a Suleiman-led administration to carry out the constitutional reforms promised by Mubarak in response to the protests. Without constitutional changes, a presidential election in September would have to run under the same rules that opposition parties say stack all the cards in favour of Mubaraks National Democratic Party and effectively foil a meaningful rival bid. The Brotherhood said discussions were still taking place among the factions to seek common ground. Until now there is no agreement among the various parties and factions on one scenario, Mohammed Morsy, a senior member of the Muslim Brotherhood, told Reuters. He said his Islamist group was proposing that the head of the Supreme Constitutional Court takes over power as stipulated by the constitution since parliament has been effectively suspended since the unrest erupted last month. The head of the supreme court will then call for parliamentary elections and the elected parliament can amend the necessary clauses in the constitution in order to conduct fair and honest presidential elections, Morsy said. Most of the clauses in the constitution concern the president ... The president has to go. We are trying to find a constitutional way out if the president is no longer in his post. Suleiman, 74, was appointed by Mubarak last week, the first time he had named a deputy since he took power almost 30 years ago. It is the post Mubarak held before he became president. Meanwhile, speaking in Munich, US President Barack Obamas special envoy for Egypt said President Mubarak must stay in power for the time being to steer changes needed for political transition. Rumors also circulated in the square that the military which has surrounded Tahrir for days was preparing to withdraw, so some protesters lay on the ground in front of tanks to prevent them. The protesters see the military as a degree of protection from police or regime supporters they fear will attack again, though the government promised Friday not to try to eject the protesters by force. The emergence of various talks and players marked a new stage in the evolution in the crisis as all sides try to shape the post-Mubarak transition. Meanwhile, US Secretary of State Hillary Clinton said that news reports of an assassination attempt on Egypts vice-president put into 'sharp relief the challenges of the standoff between government and protesters. The Fox US television news network reported late on Friday there had been an unsuccessful assassination attempt against Vice President Omar Suleiman, in which two of his bodyguards were reported to have been killed. The Middle East faces a 'perfect storm of unrest and regional leaders must quickly enact real democratic reforms or risk even greater instability, Clinton said on Saturday. The region is being battered by a perfect storm of powerful trends, Clinton said in a speech to a Munich security conference. This is what has driven demonstrators into the streets of Tunis, Cairo, and cities throughout the region. The status quo is simply not sustainable. In Egypt, saboteurs blew up a gas pipeline in northern Egypt in a further sign of the countrys instability on a 12th day of demonstrations on Saturday against the 30-year-rule of President Hosni Mubarak. State TV said on Saturday the pipeline that was attacked supplied both the Israeli and Jordanian gas lines.