The consultation was carried out after the first round of the French presidential election which saw Melenchon pick up 19.5 percent of the vote which equated to just over seven million ballots.
To the anger of many on the left and indeed frontrunner Emmanuel Macron, Melenchon has refused to urge voters to block Le Pen's path to the Elysée by backing Macron. Although he has said told his followers not to vote for Le Pen.
His France Unbowed (France Insoumise) movement instead launched a survey of supporters to find out their intentions.
The results published on Tuesday will make uncomfortable reading for Macron's camp who are becoming more and more nervous about the impact of abstentions on the vote.
Out of some 243, 000 Melenchon voters polled, 36.1 percent said they intend to cast a blank ballot. Another 29 percent said they would abstain while the remaining 34.8 percent said they will vote for Emmanuel Macron.
Voting for the far right Marine Le Pen was not included as an option.
Many of those on the far left who voted for Jean-Luc Mélenchon in the first round told The Local this week why they are going against the tide and refusing to block the far right's path to power.
“I do not want to be an accomplice to the disaster that's going to happen anyway, therefore I abstain,” Marylène Martinot told The Local.
Yannick Geffroy, another Mélenchon voter who can't abide “ultra-liberal” Macron or “fascist” Le Pen said: “Voting would legitimate the candidate who gets elected, so I can only choose militant abstention”.
Just days ahead of Sunday's keenly-watched runoff, 39-year-old Macron remains the frontrunner, with polls predicting a 19-point lead, putting him on track to become France's youngest president.
Amid concerns in his camp that a high abstention rate could help Le Pen's chances, company bosses, celebrities and scientific researchers called in newspaper editorials for people to vote for Macron, a pro-EU former investment banker who styles himself as “neither of the left nor the right”.
Macron's economically liberal approach worries many voters on the left. While they will not back Le Pen, many say they will stay at home rather than vote for him and polls say abstention could be as high as 30 percent.