I Will Not Step Down Egyptian President Mohamed Morsi has refused to step down and says he will protect democratic "legitimacy" with his life. Addressing the nation in a 45-minute televised speech he said that he had been voted for in a free and fair election and it was his job to "safeguard the revolution." Mr Morsi called for calm and said Egyptians should not attack the army, police or each other. He was, he said, attempting to get the army to return to its normal duty and withdraw its ultimatum. This appeared not to work as pro-Morsi protesters clashed with security forces at Cairo University. Mr Morsi said he would protect democratic "legitimacy" with his life According to a Health Ministry official 16 protesters were killed and dozens wounded. The speech followed a statement on Twitter in which he refused to step down and said he would not be dictated to by the military, who have given him an ultimatum to broker a power-sharing government with his political opponents. The statement said: "President Mohamed Morsi asserts his grasp on constitutional legitimacy and rejects any attempt to deviate from it, and calls on the armed forces to withdraw their warning and refuses to be dictated to internally or externally." Following Mr Morsi's speech, Khaled Dawoud, the spokesman for the National Salvation Front, said: "This is an open call for civil war ... The president continues to deny the demands of the Egyptian people that he resign. If the president refuses to cave to the demands by Wednesday evening then the army has said it will intervene, dissolving parliament and taking control of the country. Thousands protest in Tahrir Square The move has sparked fears of a "military coup" as thousands of pro and anti-government protesters gathered in Cairo, prompting violent clashes which left seven dead. Mr Morsi's address came after military sources said they would suspend the constitution, dissolve parliament and take over the running of the country if the president did not reach a power-sharing agreement with opponents. The armed forces, who took control of the country after the overthrow of Hosni Mubarak in 2011, have intensified their presence in Egypt's cities ahead of the deadline. The Foreign Office has warned against all but essential travel to most of Egypt and said any Britons in the country should consider "whether they have a pressing need to remain." During a day of high tension, the opposition announced they had chosen the leading dissident and Nobel Peace Laureate Mohamed ElBaradei to represent them in negotiations on the country's future. A protester sits in front of anti-Morsi artwork on a Cairo building The June 30 Front, which includes the Tamarod group which was behind Sunday's record protests, said it had entrusted Mr ElBaradei, who played a significant role in the 2011 revolution, to "ensure the execution of the Egyptian people's demands and to draft a scenario that aims at the complete implementation of the roadmap for the political transition." Thousands of people amassed in Tahrir Square, the birthplace of the revolution, and cities across the country as another deadline set by opposition groups for the Muslim Brotherhood's Mr Morsi to step down passed. A giant crowd also gathered outside the Qasr el-Qobba presidential palace where Mr Morsi has been working in recent days. A top Muslim Brotherhood leader urged Egyptians to stand ready to sacrifice their lives to prevent "a military coup." Mohamed al-Beltagui said: "Seeking martyrdom to prevent this coup is what we can offer to the previous martyrs of the revolution." He was referring to the more than 800 people killed during the 2011 revolution. Another spokesman said: "Egyptians are very aware that there are some people that are trying to push the country back in history and back to dictatorship."