Early this year, Ahmed Shafiq had won an appeal to his candidacy after Egyptian election officials said former regime leaders couldn't run for office. Shafiq was named prime minister Jan. 29, 2011, but resigned roughly 30 days later when Mubarak's government collapsed.
A source inside the Egyptian election commission, who spoke with the country's al-Ahram news service on condition of anonymity, said Shafiq wouldn't be banned despite a challenge this week. The source didn't provide a reason for the decision.
A spokesman for Shafiq's campaign said only that the candidate would abide by the electoral commission's decision. Several candidates were banned for various reasons, including having a criminal record. The final list of candidates was winnowed down to 13 contenders.
Egyptians head to the polls for two days starting May 23. A second round of voting is set for June should none of the candidate secure an outright victory.
The ruling Supreme Council of the Armed Forces pledged to hand power over to civilian leaders following the conclusion of the elections later this summer.