Mélenchon, a former minister in the Socialist Party government of Lionel Jospin in the late 1990s and an ex-senator, broke from the center-left party in 2008 to cofound the Left Party, which in turn formed the Left Front with the Communist Party and a range of other left-wing organizations.

Widely dismissed by political analysts as irrelevant just months ago, Mélenchon has instead forced the entire political debate to the left as his support in the upcoming presidential vote registers at 15 percent in public opinion polls ahead of the first round of presidential voting on April 22.