The Gaddafi era is still remembered by many Libyans as one of harsh autocracy, while Saif al Islam has been out of power for so long he may find it difficult to mobilise as much support as major rivals.
The son of Libya's late leader Muammar Gaddafi appeared for nearly the first time in a decade to register as a presidential candidate for a December vote planned to help end the years of chaos since his father was toppled.
Saif Al Islam Al Gaddafi, 49, appeared in an electoral commission video on Sunday in traditional brown robe and turban, and with a grey beard and glasses, signing documents at the election centre in the southern town of Sebha.
Gaddafi is one of the most prominent - and controversial - figures expected to run for president.
Other candidates are warlord Khalifa Haftar, Prime Minister Abdulhamid al Dbeibah and parliament speaker Aguila Saleh.
However, while his name is one of the best known in Libya, and though he once played a major role in shaping policy before the 2011 NATO-backed uprising that destroyed his family's regime, he has barely been seen for a decade.
New election dynamics
His formal entry into an election whose rules are still contested by Libya's squabbling factions may also cast new questions over a contest that features candidates viewed in some regions as unacceptable.
Despite the public backing of most Libyan factions and foreign powers for elections on Dec 24, the vote remains in doubt as rival entities bicker over the rules and schedule.
Educated at the London School of Economics and a fluent English speaker, Saif al Islam was once seen by many governments as the acceptable, Western-friendly face of Libya, and a possible heir apparent.
But when a rebellion broke out in 2011 against Muammar Gaddafi's long rule, Saif al Islam immediately chose family and clan loyalties over his many friendships in the West.