The 38-year-old Macron is seen as a charismatic political newcomer who may be inclined to shake things up. Almost all of his potential rivals for France's top job have issues, either in terms of governance or in policy.
Former economy minister Emmanuel Macron is set to announce Wednesday that he will seek the French presidency in 2017. The long-anticipated move has the potential to disrupt election campaigns for candidates on both the right and the left.
"He has made up his mind and the decision was taken a long time ago," an unnamed source told Reuters.
Macron was a minister in President Francois Hollande's government and served as an adviser before that, but he resigned from the government earlier this year and set up his own political movement "En Marche" (On the Move).
The organization now has more than 96,000 members and has already accumulated 2.7 million euros ($2.9 million) in donations.
The 38-year-old Macron will seek to seize the political middle ahead of next year's election. To the center-right, candidates for Les Republicains include former Prime Minister Alain Juppe and Nicolas Sarkozy, who lost the presidency in 2012 to Hollande.
Sarkozy suffered dismal approval ratings for much of his late term, and left office with support of less than 30 percent.
Marine Le Pen, head of the far-right Front National who garnered the third highest number of votes in the first round of the 2012 presidential elections, also poses a significant threat.
Fillon wins debate
Former PM Francois Fillon has been widely seen as the winner of the final debate before the vote on who gets the conservatives' candidacy in the presidential election, a poll showed. It's another upset for favorite Juppe, who has for months been ahead in polls. Whoever wins the two-round primaries on November 20 and November 27 has a strong chance of becoming France's next president.
Fillon, saw his ratings suddenly start rising a week ago and was seen as the most convincing by 39 percent of conservative and center-right voters who watched the debate on Thursday evening, versus 26 percent for Sarkozy and 25 percent for Juppe.
"The French are proud and don't like to be told what to do," he said. "Don't be afraid to contradict opinion polls and the media that had decided it all for you ... Vote for what you believe in," he said.
A social conservative with economically liberal ideas who admires late British Prime Minister Margaret Thatcher, Fillon, 62, was Sarkozy's prime minister during his five years as president in 2007-12.
Lowest approval ratings
On the left, Hollande, who is suffering the lowest approval ratings of any president in modern French history - under 20 percent, has not yet decided whether to seek a second term. If Hollande decides not to run, the Socialists would likely put forth Prime Minister Manuel Valls as their party candidate.
Macron does not plan to run as a Socialist, but would certainly seek the votes of left-wing voters disaffected by Hollande.
Macron has sought to position himself as beyond politics but the timing of his announcement - just days before the first round of primaries for Les Republicains party and their center-right allies - brought scorn from Benoist Apparu, a Juppe supporter in Parliament.
"He said, broadly - 'I am going to do politics differently, outside of political clans and parties'" Apparu said on BFM TV. "And then the first thing he does is a purely political, calculated, electoral move, telling himself, 'I will try and falsify ... the result of the center-right primary."
In France, voters do not have to belong to a political party in order to vote in that party's primary. Macron's announcement could thus compel voters planning to cast a ballot for Juppe to withhold their vote and reserve it for Macron.
A recent poll among Socialist voters found Valls leading with 70 percent, with Macron in second place at 50 percent.
bik/kl/jbh (Reuters, AFP)