From Jeremy Corbyn’s leadership of Labour to Bernie Sanders’s primary campaigns, the veteran socialists who surged to prominence in recent years often couldn’t pull the wider left behind their leadership. Yet things seem to be going rather differently for Jean-Luc Mélenchon, whose France Insoumise movement has imposed its hegemony over the established parties of the French left. His 22 percent score in April’s presidential elections, even as other weaker progressives floundered, not only defied pollsters’ expectations but put his movement in a strong position for June’s parliamentary elections.

Neoliberal hawk Emmanuel Macron remains president, following his runoff win against the far-right Marine Le Pen on April 24. Yet these upcoming elections will decide the formation of the National Assembly, and thus of the next government. This is why the Union Populaire that backed Mélenchon’s campaign has, this week, formed a new union of left-wing forces for June’s elections, also embracing the Green, Communist, and Socialist parties. Their Nouvelle Union Populaire écologique et social (NUPES) aims to make Mélenchon prime minister and stop Macron from railroading through his own agenda of pension cuts and handouts to the richest.

Bringing together such parties is a rare feat in recent history — indeed, the different forces of the French left and center left have often been implacable enemies. The neoliberalized Socialist Party, which ruled under François Hollande’s presidency in 2012–17, implemented major attacks on the French labor and welfare models, and in recent days, many figures associated with Hollande’s administration — in practice, today supporters of Macron — have fiercely denounced all talks with Mélenchon, labeling him soft on Islamism and antibusiness. Through the presidential race, he was often subject to harsh polemical attacks by the Green and Socialist candidates, while the Communists’ decision to run separately (unlike in the similar 2017 contest) was widely blamed for Mélenchon’s narrow failure to make the runoff.