There were times, during the elections here five years ago, when President Emmanuel Macron would sound almost messianic about the potential of his political party and his project for France.

This time around, with run-off votes for more than 570 parliamentary seats due on Sunday, his comments have the feel of a doomsday warning.

“Nothing would be worse than losing ourselves in blockages, and adding disorder in France to global disorder,” Mr Macron said this week.

Last Sunday, a new green-left alliance finished neck and neck with Mr Macron’s allies in the first round of voting. If they continue to do well this weekend, they could deny the president a majority in parliament, making it harder for his government to act.

“For most of my life, I’ve been voting for the lesser of two evils,” 31-year-old Romain told me at a rally in Toulouse. “Now finally, for the first time in my life, we have a big alliance on the left and it’s exciting.”

The new alliance, called Nupes (New Ecological and Social Popular Union) brings together Socialists, Communists and Greens under the leadership of France’s far-left leader Jean-Luc Mélenchon.

They’re focusing on climate change and social solidarity, though many of their members openly admit to big policy differences on other issues.

Analysts say they’re highly unlikely to win a majority themselves, but Nupes candidate in Toulouse, François Piquemal, insisted that with more than 400 candidates running in the second round, nothing was impossible.

“Mathematically it’s possible,” he said. “And in politics, from the moment things are mathematically possible, we can achieve them. Three months ago people thought it was impossible for all the components of the left to come together behind a common programme. That is what’s happening today.”

It’s the kind of zeal that gripped Mr Macron’s candidates last time. And even gains short of a majority could still spell trouble for Mr Macron’s government.

“They are going to be loud,” Edouard Lecerf, deputy director of polling institute BVA, told me. “They are going to be able to slow things down. Nupes is going to make noise.”