French voters are going to the polls in the final round of key parliamentary elections that will demonstrate how much legroom President Emmanuel Macron’s party will be given to implement his ambitious domestic agenda.

In last week’s first vote, the left, under firebrand Jean-Luc Melenchon, made a surprisingly strong showing, sending jitters through Macron’s allies.

They fear that a strong showing from Melenchon’s coalition on Sunday could turn Macron into a shackled second term leader, one who spends his time bargaining with politicians and with major limits placed on his ability to rule.

Elections are being held nationwide to select the 577 members of the National Assembly, the most powerful branch of France’s Parliament.

Though Macron’s centrist alliance is projected to win the most seats, observers predict that it could fall short of maintaining his majority — the golden number of 289 seats. In this case, a new coalition composed of the hard left, the Socialists and the Greens may be forged, one which could make Macron’s political maneuvering harder since the lower house of parliament is key to voting in laws.