Under French law, a candidate needs 500 signatures from elected officials in at least 30 different departments across the country or in France's overseas territories.
While this is an easy feat for candidates from the main parties, the governing UMP and the opposition Socialists, it can be a challenge for smaller candidates.
Even Marine Le Pen of the far-right Front National, who has the support of around 15 percent of voters according to the most recent poll, expects to have difficult getting the necessary number of sponsors.
Her father, Jean-Marie Le Pen, who led the party before her, failed to get the necessary numbers in the 1981 election which saw François Mitterrand win power.
She announced at a press conference on Tuesday that she had written to Prime Minister François Fillon to ask for a change in the law so that those signing can remain anonymous. Current rules stipulate that the signatories for each candidate be published.
"If the prime minister refuses, he will take the responsibility for this refusal," she said, "in the eyes of France and in the eyes of the world."
She declined to give the number of signatures she already has, although she will certainly have 118 as a minimum based on the number of elected officials the party has around the country.
Other candidates are struggling to get the necessary votes.
Christine Boutin, a former housing minister under President Sarkozy who is standing separately as head of the Christian-Democratic Party, has around 100 signatures according to Le Parisien newspaper.
"I come from a family of hunters and I'm here to hunt down some signatures," she told the newspaper as she stalked the corridors of the mayors' conference in Paris on Tuesday looking for sponsors.
Philippe Poutou of the Anti-Capitalist Party (Nouveau Parti anticapitaliste) has secured 220 signatures while political heavyweight Jean-Pierre Chevènement of the Republican and Citizen Movement (Mouvement républicain et citoyen) has 250, according to Le Parisien.
The mayors themselves complain of constant solicitations for their support.
"I'm inundated with so many calls that I've started telling them I'm a candidate myself," said one, Jean-Claude Boistard.
Another said he would not be supporting anyone to avoid controversy.
"In my village, we don't advertise our opinions," said Dominique Schaeffer. "As the signatures are made public, I won't be supporting anyone. I'd get in trouble."
The last presidential election in 2007 fielded 12 candidates, including four communists, one green and the well-known anti-globalization activist José Bové.