As a popular uprising against the rule of Egyptian President Hosni Mubarak shows no sign of letting up, the question of what people or groups could take a stake in power is fast rising to the fore.
Throughout his three decades in power, Mubarak's government has systematically weakened and manoeuvred against all the opposition parties.
Emergency laws have been invoked to restrict party activities and an Interior Ministry-run committee has prevented a large number of parties from obtaining formal licences, including the Islamist Muslim Brotherhood.
As a result, professional unions, civil rights organisations, the judiciary, newspapers and other groups have played a role in Egypt's atomised opposition movement.
Here are some of the people and groups whose names could figure in the coming days:
The 68-year-old former head of the International Atomic Energy Agency (IAEA), returned to Egypt in 2010 after a career that saw him win a Nobel peace prize in 2005. A lawyer by training, he immediately threw himself into the political arena saying Egypt needed a complete overhaul and an end to the authoritarian rule of a military man like Mubarak. He disappointed many democracy activists by spending much time outside the country in recent months, but returned on Thursday stating he was ready to take any role in a transitional government and later addressing protesters at Tahrir Square in central Cairo.
Badie, 66, became leader of Egypt's biggest opposition group last year. The Brotherhood is run on a collegiate basis, with a number of figures who often speak in its name such as Essam al-Erian or London-based Kamel El-Helbawy. But if it were to enter into talks with the government it would be on the authorisation of its "murshid 'aam", or general guide, Badie. Badie is seen as a conservative, in the typical mould of Brotherhood leaders, who was reluctant to challenge the authorities for fear of provoking more repression. Mubarak has made fending off the Islamists a major plank of his policies, accusing them of subverting last week's protests and provoking the looting and disorder. The government says the Brotherhood is a banned organisation but allows it to operate within limits.
A liberal politician and trained lawyer, Nour was Mubarak's rival in the 2005 presidential election but suffered for his impertinence. He was jailed after conviction for submitting forged documents when setting up his Ghad (Tomorrow) party. He was released after serving more than three years of a five-year term. The law as it stands bans him any political office for at least five years after the end of his original jail term, which would rule out running in elections in September. Nour served previously as a parliamentarian for the Wafd party, which he left.
The secretary general of the Arab League was a popular foreign minister under Mubarak, celebrated by singers for his populist pro-Palestinian rhetoric during years of Arab-Israeli peacemaking. His move to the Arab League, a conservative organisation that backs existing Arab rulers, has tarnished his image somewhat but he has been cited in the past by many Egyptians as someone they would support as president. He has been vocal since the protests began, saying on Sunday he wanted to see multi-party democracy in Egypt.
Egyptian winner of the Nobel Prize for Chemistry in 1999, Zewail said last year he had no political ambitions. However, newspapers said on Monday he would return on Tuesday to continue work in a committee for constitutional reform including Ayman Nour and prominent lawyers. Al-Shorouk newspaper published a "letter to the Egyptian people" in which he proposed a "council of wise men" to write a new constitution.
A popular Arab nationalist politician who leads the Karama party that has never achieved formal licencing from the government. Elected to parliament in 2005, Sabahi considered running in the presidential elections that year after Mubarak introduced amendments under pressure from Washington but later changed his mind. He was expected to attempt a bid for the presidency this year.
Respected trade union leader George Ishak founded the Kefaya movement in 2004 that galvanised protests against Mubarak's rule in 2005 around the idea of rejecting his son Gamal as a future president. The movement, which appealed to middle class professionals, subsequently lost its momentum amid internal dissent but when protests began last week Kefaya appeared to play a role in mobilising them.
The Wafd party, with its roots before the 1952 military coup, has traditionally been the bastion of liberal democrats in Egypt. But it is seen as having been coopted by Mubarak's government in recent years. The leftist Tagammu has played a similar role. Magdy Hussein, leader of the Islamist Labour party, is a popular opposition figure who has frequently been in and out jail.
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