RN and its allies already have 38 confirmed seats, won outright with more than half the local vote in Sunday’s first round. The Popular Front have 32 and the Macron alliance just two, an indication of how far behind the governing party has fallen.
Another 501 seats have yet to be decided and the big three party blocs have big decisions to make within the next 24 hours.
Candidates who have qualified for Sunday’s second round for the Macron camp or the Popular Front now have until 18:00 on Tuesday to decide whether or not to withdraw, to maximise the chances of a political rival defeating National Rally.
Both the Popular Front and the Macron Ensemble camp have pleaded with voters not to vote for the far right.
But tensions between the two burst out into the open on Monday, an indication of the high stakes of this election and the intensity of such a brief campaign.
Greens leader Marine Tondelier was on the verge of tears during a radio interview, when she reacted angrily to a Macron minister’s call not to back the biggest party in the left-wing alliance.
Finance Minister Bruno Le Maire had said moments earlier that voters should steer clear of France Unbowed, whose critics denounce it as extremist, as much as they should not vote for Mr Bardella’s party.
Ms Tondelier said for 10 years she had lived in a town held by National Rally’s Marine Le Pen, and that the Macron alliance had misunderstood the issue and had chosen dishonour and cowardice.
“Does National Rally have a chance of winning an absolute majority in the National Assembly? The answer is yes. Is France Unbowed in the position of winning an absolute majority, the answer is no.”
What is so unusual about this election is that more than 300 of the local races are run-offs between three candidates.
Sunday’s turnout of 66.7% was the highest since 1997, which meant more candidates than ever qualified for the second round.
But by Monday afternoon a large number of third-placed candidates had pulled out of the race, according to Le Monde, including those standing for Ensemble and the individual parties in the Popular Front.
One of RN’s leading figures, Sébastien Chenu, said he was confident that even if his party did not reach the 289 seats it would succeed in “finding supporters” in the new National Assembly.
He said there might be MPs keen on preventing the Assembly from becoming blocked, and if that was possible “we will assume our responsibilities before the French people”.