PARIS (Reuters) - Former French economy minister Emmanuel Macron will decide by Dec. 10 whether to stand in next year's presidential election, a spokesman said on Tuesday, a likely independent candidate who could split voters in both right-wing and left-wing camps.

One of France's most popular politicians, Macron joined the Socialist government in 2014, quit his ministry this year and has sharply criticized President Francois Hollande's administration since. He is not a member of the party.

"He is in the process of finalizing his decision. If he decides to be a candidate, he will announce it between now and a big rally on December 10," Sylvain Fort told Reuters.

"At this stage, he has not yet made a decision," Fort said.

Aides have said the 38-year-old former investment banker will not take part in the Socialist primaries that are due to take place in January amid party infighting and abysmal approval ratings for Hollande himself. The election is in April and May.

Macron has instead launched his own political movement called "En Marche" or "Forward" and so would probably stand as an independent.

Hollande has yet to confirm his own candidacy, but polls show no leftist candidate has much of a chance in 2017 anyway.

Macron is seen as a potential threat to candidates from the right as well as the left, including front runner Alain Juppe, who is targeting the same center ground, and who will fight it out with former president Nicolas Sarkozy in November for the center-right nomination.

Macron was credited with as much as 18 percent of first-round presidential votes in a Kantar Sofres OnePoint poll published last month in Le Figaro newspaper, but would fail to reach the second round runoff with that score.

(Reporting by Emmanuel Jarry Writing by Sudip Kar-Gupta and Andrew Callus; Editing by Michel Rose and Louise Ireland)