Sarkozy resigned Thursday from the Constitutional Council, a body that includes former presidents, Radio France Internationale reported. That, and his call for funds, suggest he may be planning a return to elective politics.
A source in the Union for a Popular Movement, Sarkozy's political party, said 900,000 euros ($1.155 million) had been donated online by Saturday morning.
More money is expected to be in the mail.
Catherine Vautrin, the party treasurer, said the UMP will be on a sound financial footing if members donate an average of 35 euros ($45) each.
Sarkozy's resignation followed a court ruling that he overspent during the 2012 election. That means the party lost state campaign reimbursement.
On his Facebook page, Sarkozy said he was leaving the council because he wanted to be able to speak freely and to be able to "guarantee freedom of democratic expression in our country." He then made his plea for funds for the UMP.