President Emmanuel Macron's La Republique En Marche! (LREM) political movement is set Sunday to win a sweeping parliamentary majority in a run-off vote.
After securing 32 percent of the vote in the first round, LREM and its ally, the centrist MoDem party, are tapped to gain between 440 and 470 seats in the National Assembly's 577-seat chamber -- far more than the 289 necessary for an absolute majority.
The victory for LREM, a movement launched by Macron less than a year ago, is considered a slap to mainstream parties, including the Socialist party that received less than 10 percent of the vote and will translate to a loss of 90 percent of its lawmakers.
Conservative Republicans and their allies trail in second place with 22 percent and polls shows them winning between 70 and 90 seats.
The Socialist Party and its allies are projected to win 20 - 30 seats, far less than its current 277 seats.
Jean-Luc Melenchon's left-wing La France insoumise (Unbowed France) party and the Communist party allies are expected to hold eight to 18 seats.
The far-right National Front of recently defeated presidential candidate Marine Le Pen is predicted to have between one and five lawmakers.
If those figures hold, it would mean Le Pen's and Melenchon's parties would not be able to form a parliamentary group.
A Macron victory of that proportion would be the biggest majority in France since Charles de Gaulle's landslide win in 1968.
It could be marred, however, by record low turnout that was registered in the first round and feared in the run-off-putting into question the government's legitimacy.
Voter turnout hit an historic low in the first round with abstention reaching 51 percent, the most since 1958, according to Interior Ministry data.
Abstention is predicted to again reach 53 - 54 percent in the run-off -- much higher than the 45 percent in the last 2012 election.
Prime Minister Edouard Philippe has urged voters to go to the polls Sunday and cast ballots.
"It's the same message here as everywhere else: No one should abstain," Philippe said while campaigning Thursday in southern France. "In France voting is not obligatory ... it is a right and a responsibility."
Abstention is partly blamed on voter fatigue as voters have casts their ballots in two parties' primaries in the last eight months. That was followed by two rounds of presidential polls and, now two rounds of parliamentary elections.
In addition, there is a "massive indifference of the French electorate to the parliament", sociologist Albert Ogien told French radio RFI.
Macron needs an absolute majority in the National Assembly, the lower and more powerful house of parliament, to get his reform bills passed and govern at ease for the next five years.
Polls close at 8 p.m. local time (0600 GMT) in large towns and first estimates will follow.
The Senate, the upper house, will be elected Sept. 24 by an electoral college.
