PARIS, April 20 (Xinhua) -- An opinion poll published on Thursday predicts that a runoff vote will be held for centrist candidate Emmanuel Macron and far-right candidate Marine Le Pen in the upcoming presidential election in France.

The poll, conducted by market research firm Harris Interactive for the French national broadcaster, estimates that Macron and Le Pen will lead in the first round of votes on Sunday, winning 25 and 22 percent respectively.

Two other frontrunners right-wing Francois Fillon and far-left Jean-Luc Melenchon are both expected to garner 19 percent of the votes, followed by Socialist Benoit Hamon at 7.5 percent, while the other six candidates below the threshold of 5 percent.

The forecast indicates a tight battle among the four frontrunners, as most of their supporters interviewed said they wouldn't not change their minds.

Regarding the outcome of the second round, scheduled for May 7, the poll predicts that Macron will defeat Le Pen by 66 against 34 percent.

In other scenarios, if Macron faces off Fillon in the runoff vote, he is expected to have a clearer victory by 68 against 32 percent; if he goes against Melenchon, he will win by 60 against 40 percent, according to the poll.

The poll also indicates that if Le Pen and other two frontrunners enter the second round, she will lose by 40 against 60 percent to Melenchon, and 42 against 58 percent to Fillon.