Egypt's popular uprising against President Hosni Mubarak may not have succeeded in forcing his immediate resignation - yet - but his announcement on Tuesday that he would not run for re-election in September leaves the door open to a number of possible candidates to succeed him.

Much can happen in the eight months leading up to the election. Indeed, many of the protesters continue to call for him to leave office, suspicious that he might change his mind and extend his 30-year rule indefinitely.

But speculation has already begun on who will seek to fill Mubarak's shoes. Here is a look at some of the names in the conversation.

Mohammed ElBaradei

A former head of the International Atomic Energy Agency and a Nobel Peace Prize laureate in 2003, 68-year-old ElBaradei returned to Egypt from his home in Vienna as the protests were gathering momentum.

He has taken part in much of the demonstrations and been a popular spokesman for the opposition in the international media. But despite his high global profile, he is relatively unknown in his own country. Some Egyptians have even criticized his long residence abroad, implying his connection to Egypt has grown stale.

But since his return to Egypt, ElBaradei has shown interest in nothing but regime change and democratic reform. In an interview last year with the opposition-leaning Egyptian daily Al-Masry Al-Youm, he said his goal was to unite the scattered opposition in Egypt: "We can't afford the luxury of people from the left fighting with the right, the socialists fighting with the Muslim Brotherhood, the Copts fighting with the Muslims."

Omar Suleiman

In an attempt to appease protesters last Saturday, Mubarak fired his cabinet and named Omar Suleiman his first-ever vice president. Suleiman, like Mubarak, got his start in the Egyptian military and, in 1993, took over as head of the Egyptian General Intelligence Service.

In that position, he played an important diplomatic role in the Israeli-Palestinian conflict and acted as a mediator between the various Palestinian factions, in particular, Fatah and Hamas. He fostered close ties with the United States and is seen as highly influential, but also as someone who works in secret.

Because of his closeness to Mubarak, Suleiman's appointment was viewed by most protesters with skepticism and mistrust - something that does not seem likely to change.

Gamal Mubarak

Up until the start of Egypt's protests, the succession of President Mubarak's son Gamal seemed a foregone conclusion.

Both a businessman and a political figure, Gamal Mubarak has been groomed by the president as his heir apparent for years, likely to take over after the 2011 elections.

But the eruption of protests - which have also targeted the president's son - have thrown Gamal Mubarak's candidacy into doubt. International leaders have joined protesters' calls for him not to run, but neither Gamal, nor President Mubarak, have clearly stated their intentions.

Fathi Sorour

Another figure closely associated with the Mubarak regime is Fathi Sorour, speaker of the People's Assembly and veteran leader of Mubarak's National Democratic Party.

When the position of vice president was still vacant, Sorour was second in line to Egypt's presidency. If Mubarak had resigned or died in office, Sorour would have become interim president for 60 days until new elections could be held. But the constitution would forbid him from running for president after that time.

Sorour's closeness to Mubarak would likely rule out any support from the opposition.

Farouk Sultan

Farouk Sultan is chairman of the Supreme Constitutional Court of Egypt. The justices have a good reputation among Egyptians, not unrelated to their refusal to act as observers in the 2010 parliamentary elections because they saw electoral fraud as inevitable.

The constitutional judges are known for taking part in demonstrations critical of the government, particularly of the emergency law under which Mubarak has governed for all his 30 years in office.

Sultan is not as well known as the other candidates. But various opposition movements have called for parliament to be dissolved, in which case Sultan would become interim president for no more than 60 days - sure to raise his profile among voters.

Ayman Nour

Liberal politician and attorney Ayman Nour founded the opposition party El Ghad, which was formally recognized in 2004. He ran against Mubarak in the 2005 presidential elections - the first under Mubarak that allowed multiple candidates - and won second place.

But shortly after the elections he was arrested for allegedly falsifying documents that established his party. Nour vehemently denied the charges from prison and the move was widely seen as an act of suppression.

Nour sat in prison until 2009, when he was released for what officials said were medical reasons. He then restarted his political activism and gained popularity, especially among the liberal, urban youth.

According to current law, Nour's imprisonment labels him a criminal and bars him from running for president. Whether that law could be changed in the lead-up to the election is unclear.

Amr Moussa

Amr Moussa has been Secretary General of the Arab League since 2001, after serving as Egypt's foreign minister for ten years. He gained some popularity in that time for his criticism of Israel, and it was rumored that Mubarak got him the position in the Arab League to get rid of a potential rival.

Moussa was the first to publicly announce he was considering running for president this year, telling US broadcaster CNN that he would "think (about) it seriously in the next few weeks."

His past rhetoric may not have won him points with the US or Israel, but it may give him a boost with Egyptian voters.

Mohammed Badie

As "general guide" of the Muslim Brotherhood, Egypt's biggest opposition party, Mohammed Badie is an obvious possibility for the country's highest office. An official ban on the Brotherhood has not stopped many members from running as nominal independents, and parliamentary elections in 2005 gave the party 20 percent of the vote.

Badie is seen as a conservative, and the Brotherhood's Islamist ideology makes him an unpopular choice among Western countries and Israel. US State Department spokesman P.J. Crowley acknowledged that the hard-line party was "a fact of life in Egypt," and called on its leaders to respect the democratic process.

Badie released a statement for the Brotherhood, saying the party did not recognize any government decisions made since January 25, the day the protests started, and that it would not participate in negotiations with Mubarak or members of his regime.

Authors: Hebatallah Ismail-Hafez, Marco Müller / acb
Editor: Nicole Goebel