PARIS (Reuters) - French voters view far leftist Jean-Luc Melenchon as the strongest opponent of President Emmanuel Macron, according to a new poll on Tuesday that highlights the weakness of mainstream opposition.

FILE PHOTO: Member of parliament Jean-Luc Melenchon of La France Insoumise (France Unbowed) political party attends the questions to the government session at the National Assembly in Paris, France, July 12, 2017. REUTERS/Charles Platiau

The Ifop-Fiducial poll showed Macron’s popularity has dropped sharply since he took power in May but its key finding could help him as he embarks on reforms because polls show voters see Melenchon as too extreme to be a serious candidate for power.

“Melenchon is very much on the protest front but not seen as an actual alternative (to Macron),” said Frederic Dab of Ifop pollsters.

“That can be an opportunity for Emmanuel Macron, allowing him to create a vacuum around him and replace the left-right divide by a reform vs protest debate.”

The poll for Paris Match and Sud Radio showed 45 percent of voters say Melenchon’s ‘France Unbowed’ party provides the strongest opposition to Macron.

That is more than twice the figure for the conservative Republicans (LR) or the far-right National Front (FN). Only 8 percent mentioned the Socialists. France Unbowed has been much more vocal than the conservatives or Socialists.

The Republicans have been subdued in the wake of their defeat in the presidential election and divided over what stance to take toward Macron, whose economic policies resemble what many in their party have asked for for years.

All three parties are struggling to get their voices heard above Macron and Melenchon’s criticism of each other.

“Macron is trying to eliminate anything there is between him and extreme parties. I won’t let him do that ... I won’t resign myself to Melenchon being the only opposition to Macron,” Laurent Wauquiez, the frontrunner to win LR’s leadership in December, said on Sunday.

A government source said Melenchon’s relative strength was welcome and he was Macron’s only proper opponent.

“I was praying to have Jean-Luc Melenchon and Marine Le Pen in parliament ... The Emmanuel Macron/Edouard Philippe alliance was meant to get the Socialist Party and the right to explode and we are not disappointed,” the source said.

He was referring to the fact that Macron’s prime minister Philippe comes from LR.

Melenchon strongly opposes Macron’s plans to overhaul labor laws but his party can do little to block the measures because it has just 17 lawmakers in the 577-strong parliament.

Melenchon, an anti-NATO euroskeptic known for his fiery debating style, has called on his supporters to march on Sept. 23 to protest the labor reforms, which will give companies more flexibility on firings, pay and working hours.

The poll confirmed Macron’s drop in popularity with 46 percent saying they approved of his policies, down 10 points from July.