How does this 500 signatures rule work?
It is quite simple: for a candidate to be allowed to run for president, he or she needs 500 written endorsements from elected officials. Those signatures have to be sent to the Constitutional Council by the end of today.
Those signatures must come from at least 30 different regional departments.
This rule was created to make sure there wouldn't be too many minor candidates running for France's top position, but it has been criticised several times by politicians, notably far-right Marine Le Pen and far-left Jean-Luc Mélenchon.
"Of course our system isn't perfect because some candidates get endorsements while their political weight doesn't justify the existence of their own candidacy," says Thomas Guénolé, a political analyst with Sciences Po. "However, it's a good system because all political trends are in the race. It's not intellectually satisfying, but in practice it works."
Which candidate has gotten his or her 500 signatures?
Eight candidates so far, including the five main contenders, far-right Marine Le Pen, centrist Emmanuel Macron, right-wing François Fillon, Socialist Benoît Hamon and far-left Jean-Luc Mélenchon.
Fillon has even reached 3,000 signatures.
There were questions about whether smaller far-left candidates, such as Philippe Poutou, would be able to reach the threshold.
The final list will be announced on Saturday by France's Constitutional Council.
The campaign will officially start next Monday. What are the opinion polls saying?
Most opinion polls project Le Pen will get around 26 percent of the vote in the first round, with Macron and Fillon trailing behind, while Hamon is around 15 percent and Jean-Luc Mélenchon 11 percent.
For the second round of the upcoming election, forecasts predict we could see a match between Le Pen and either Macron or Fillon... both are given winner against her.
Another study done by the Sciences Po Political Research Centre (CEVIPOF) says that only 66 percent of the French are certain to go vote.
"That number is not normal, and it's quite low if you're comparing it to what it was in 2012," explains Bruno Cautres, a researcher with the CEVIPOF. "The campaign is not over yet, but the low turnout is good news for Marine Le Pen, because her voters are extremely motivated."
Another poll this morning said 75 percent of French people want François Fillon to withdraw his candidacy. Could that happen?
It doesn't seem likely given the support Fillon is enjoying from his conservative Les Républicains party.
"It will not happen," says Bruno Cautres. "It's too late and the party supports him. The right-wing electorate wants to win this election, so it could explain why they're supporting François Fillon despite having been disillusioned."
Could the polls prove to be wrong?
They could. With the campaign officially starting on Monday, things could change drastically.
"Half the voters don't know who they are going to vote for", says Thomas Guénolé. "Until the very last days, or even hours, you will still have one quarter of the population who doesn't know who they're going to vote for. Predictability is near zero, so anyone saying 'I know what's going to happen' isn't serious."
The next stop for the candidates is the first TV debate next Monday.
It will be the first time all the major candidates -- Le Pen, Macron, Hamon, Fillon and Mélenchon -- confront each other since the beginning of the campaign.