Momentum was building on Monday behind attempts by French left-wing parties to form a united front against President Emmanuel Macron in next month's parliamentary elections, after radical Jean-Luc Mélenchon clinched a deal with the Greens.
Macron was re-elected for a second term last month, but he needs support from a majority of lawmakers to push through a pro-business and pro-EU legislative agenda that also includes a plan to increase the retirement age.
Early polls for the June 12-19 elections suggest he could achieve that, but opposition parties on the left and right are negotiating tie-ups in the hope of controlling parliament and thereby blocking Macron's reforms.
Mélenchon, who heads the hard-left France Insoumise (France Unbowed, or LFI) party and almost pipped far-right leader Marine Le Pen to contest the presidential runoff against Macron, is pressing for an unprecedented alliance with the Greens, the Communists and the Socialists.
The Greens and LFI hailed Monday's deal as a "historic moment" and said agreements with other parties of the left would follow.
The Communist Party could join them imminently, its presidential candidate, Fabien Roussel, told reporters, though differences remained over which constituencies would be reserved for his party.
A Harris Interactive poll from April 24-25 showed a united left garnering 33 percent of the legislative vote, the same as an alliance of Macron's party and the conservatives, though under the two-round system that could well translate into a majority of seats for the president.
The same poll put the far right on 31 percent, though at that end of the political spectrum, moves to build an alliance are less clear-cut, with Le Pen and extreme-right rival Eric Zemmour fiercely at odds.
Meanwhile, members of conservative party Les Républicains are torn between wanting to join Macron's coalition, remain independent or gravitate towards Le Pen's nationalist camp.
'We're not Frexiters'
Mélenchon's attempts to add the Socialist Party, the former dominant force on the left, to his alliance also appear tricky.
Negotiations between them and the LFI were briefly suspended last week, with their respective stances on the EU a major sticking point.
In Mélenchon's deal with the Greens, the two parties said that, even if they agreed France should not exit the EU or abandon the euro, they were "ready to disobey European rules", including on budgets and competition issues.
Socialist party head Olivier Faure baulked at the idea. "We're not Frexiters," he said on Sunday. He did however agree that some EU some free-market policies needed reforming, and he and Mélenchon were seen hugging during May Day demonstrations.
Mélenchon served as a Socialist minister in the early 2000s but broke from the party in 2008, three years after he defied the party line by campaigning against a draft European constitution that he feared would enshrine neoliberal economics in EU law. He also wants France to leave NATO.
His deal with the Greens includes plans to lower the retirement age to 60, raise the minimum wage and cap prices on essential products.
Suggesting Macron's allies were taking the threat from the left seriously, his lieutenants went on the attack on Monday.
"Selling yourself to France Insoumise [France Unbowed], a europhobic and nationalist party, in exchange for a few constituencies says it all about the ideological collapse of the Greens," Pieyre-Alexandre Anglade, a lawmaker in Macron's party, tweeted.
(FRANCE 24 with REUTERS)
