(Bloomberg) -- Leaders of France’s left-wing parties, which have papered over deep-rooted differences to form a bloc to fight in the country’s snap legislative elections, called for unity in their first campaign rally on Monday evening.

Hundreds of people gathered in a square in Montreuil, on the outskirts of Paris, in support of the New Popular Front, an alliance of parties spanning Socialists, Communists, Greens and far-left France Unbowed. The bloc was hastily cobbled together last week after President Emmanuel Macron dissolved the National Assembly and called for a new vote after his political group was trounced by the far-right National Rally in European Parliament elections.

“Together, let’s make a pledge to never abandon each other,” Olivier Faure, the head of the Socialist party, told a cheering crowd. Leaders of the Communist party and France Unbowed also urged supporters to remain united.

With significant differences on multiple issues, the New Popular Front alliance remains fragile, and is keen to avoid fragmenting the left-wing vote by public infighting in the two weeks until the first round of voting on June 30. The parties came together primarily to block the far-right National Rally of Marine Le Pen and also to weaken Macron’s party.   

Polls show that the leftist bloc is on track to form the second-largest group, behind Le Pen’s National Rally. 

Still, for all the calls for unity, differences remained visible. Two of the most prominent figures in the bloc — far-left firebrand Jean-Luc Melenchon, of France Unbowed, and Raphael Glucksmann, a pro-European leader — didn’t show up. And although the gathering was a New Popular Front rally, militants carried flags of their respective parties.

On Sunday, in an effort to stabilize the alliance, Melenchon said that he was prepared to let someone else become prime minister if the New Popular Front wins a majority. A Melenchon protege who had previously been convicted for domestic violence also withdrew from the election, following a backlash from other parties.

The new leftist alliance has yet to overcome significant divisions between its members, notably over military support for Ukraine and Melenchon’s refusal to consider Hamas a terrorist organization. On economic policy, France Unbowed also has much more radical proposals than the Socialists.

In the crowd in Montreuil, many reckoned the bloc will remain fragile. Juliette Fey, a 26-year-old student, said she expects the divergences to blow up even if they win the elections. 

“Now we must focus on winning but I don’t see our political differences going anywhere,” she said. “These differences are just too big.”  

©2024 Bloomberg L.P.