PARIS (Reuters) - French left-wing firebrand Jean-Luc Melenchon said he would run for the presidency again next year, a move that risks splitting the left-of-center vote and hurting Socialist President Francois Hollande’s chances of re-election.

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Hollande, who is widely expected to announce a cabinet reshuffle on Thursday to prepare for the 2017 election, has tried to discourage candidates to his left, arguing this could prevent any left-of-center politician reaching the second round runoff.

Melenchon, 64, a former Socialist lawmaker who has become a staunch critic of Hollande, could draw votes away from the president, who already faces an uphill battle for re-election due to public anger over high unemployment and other factors.

“I am presenting my candidacy for 2017,” Melenchon said on a video posted on his website late on Wednesday. “This election can be a chance for the people. It is the opportunity to turn the page peacefully and democratically on an unfair and cruel system that our country and continent are sinking into.”

Melenchon gained 11.1 percent of the votes in the first round of the last presidential election in 2012, helped by Communist backing.

Their Left Front union has not fared well in local elections since then, but a Viavoice poll on Tuesday showed Melenchon himself remains popular, with 10 percent of left-wing voters considering him the best candidate for the Left in 2017, only three percentage points behind Hollande.

In French presidential elections, only the top two candidates in the first round of voting make it to the run-off.

Opinion polls currently show far-right party leader Marine Le Pen reaching the second round, leaving the other spot most likely to either ex-president Nicolas Sarkozy’s conservative party or Hollande’s Socialists. This means even a few percentage points for Melenchon could determine who makes it to the second round.

“He (Melenchon) is dividing his own camp,” French Health Minister Marisol Touraine told France 2 television.

Melenchon has not struck an alliance with the Communists this time and it is unclear how he will finance his campaign.