Less than two weeks after France’s neoliberal president, Emmanuel Macron, defeated the far-right’s Marine Le Pen to win a second five-year term, the country’s four major left parties have agreed in principle to form an electoral coalition that aims to deny Macron a parliamentary majority.

“No one on the left can win on their own.”

France’s center-left Socialist Party and Jean-Luc Mélenchon’s far-left France Unbowed reached a draft agreement on Wednesday following extensive negotiations. The French Communist Party and Greens had already agreed to join the alliance earlier this week.

“We want to elect MPs in a majority of constituencies to stop Emmanuel Macron from pursuing his unjust and brutal policies and beat the far-right,” the Socialist Party and France Unbowed said in a joint statement, according to Agence France-Presse.

The pact was spearheaded by Mélenchon, who finished just behind Le Pen in the first round of France’s presidential election and therefore missed out on a chance to challenge the incumbent one-on-one.

If the deal is confirmed—it still needs to be approved by the Socialists’ national committee on Thursday—all four parties “will campaign under a common program and run one joint candidate in the election for the National Assembly on June 9 and 12,” Politico reported. “The agreement would reportedly allow a Socialist candidate to run unopposed in 70 constituencies.”

BBC News underscored the potential significance of the coalition: “Instead of running against each other in the parliamentary elections, Socialists, Greens, Communists, and supporters of France Unbowed will share one candidate per constituency, thus greatly increasing their chances.”

“After Macron’s win, Mélenchon immediately called on voters to ‘elect him prime minister’ and hand the left a National Assembly majority,” AFP reported. “A united left ahead of the parliamentary poll is ‘an unprecedented and important event,’ political historian Gilles Candar told AFP—although he added that it remains to be seen whether it can secure power or remain coherent.”

If the left-wing coalition succeeds in winning a parliamentary majority and Mélenchon becomes prime minister, it could systematically block Macron’s pro-corporate agenda.

Macron, a former investment banker, has reduced the corporate tax rate and is currently pushing an unpopular plan to raise the retirement age from 62 to 65. In addition to exacerbating economic inequality and insecurity, Macron’s pursuit of anti-immigrant and anti-Muslim policies has legitimized Le Pen’s far-right ideas, progressive critics say.

If Mélenchon’s proposed alliance is finalized, it would constitute “the first formal coalition for the French left since the Socialist-Green pact two decades ago,” Politico noted. “If the deal goes ahead, the parties will campaign on policies including raising the minimum wage, capping prices on essential products, and lowering the retirement age to 60.”

Pierre Jouvet, a negotiator for the Socialist Party, told reporters: “I believe that today we are a few hours away from a historic moment, a historic moment that has been awaited for years by the people of the left who have been ardently asking us to find a way to come together.”

“No one on the left can win on their own,” Communist Party leader Fabien Roussel told France Inter radio, adding that the coalition needs to harness “the immense hope among the French public, among workers, among young people who are asking us to unite.”