By Juliette Jabkhiro and Layli Foroudi

PARIS (Reuters) – Marine Le Pen’s far-right Rassemblement National (RN) party made a historic gain in the first round of French parliamentary elections on Sunday, post-election polls showed, but the final outcome will depend on days of horse-trading ahead of a runoff vote next week.

According to polls by Ipsos, Ifop, OpinionWay and Elabe, the RN was polling at around 34 percent of the vote, a major setback for President Emmanuel Macron, who called for new elections after his candidate was crushed by the RN in the European elections earlier this month.

The RN was well ahead of its left-wing and centrist rivals, including Macron’s Together bloc, whose vote was forecast to win 20.5% to 23%. The New Popular Front (NFP), a hastily assembled left-wing coalition, was forecast to win around 29% of the vote, according to the polls.

The poll results were in line with pre-election opinion polls and were greeted with cheers by Le Pen’s supporters, but left little to say about whether the anti-immigration and eurosceptic RN will be able to form a government that “coexists” with the pro-European Macron after next Sunday’s runoff vote.

Long a pariah for many French people, the RN is now closer to power than ever. Le Pen has sought to burnish the image of a party known for racism and anti-Semitism. It’s a tactic that has worked in the face of voter anger at Macron, the high cost of living and growing concerns about immigration.

In Le Pen’s Henin-Beaumont constituency in northern France, supporters waved French flags and sang the Marseillaise.

“The French have shown their willingness to leave behind a despicable and destructive power,” Le Pen told the cheering crowd.

The RN’s chances of coming to power next week depend on the political arrangements made by its rivals in the coming days. In the past, centre-right and centre-left parties have joined forces to keep the RN out of power, but this dynamic, known as the “Republican Front”, is more uncertain than ever.

If no candidate receives 50% in the first round, the top two candidates automatically qualify for the second round, as do all candidates with 12.5% ​​of registered voters. In the runoff, the candidate who receives the most votes wins the constituency.

The high turnout on Sunday suggests that France is heading for a record number of three-candidate runoffs, which experts say tend to benefit the RN much more than two-candidate races.

The horse trading began almost immediately on Sunday evening.

Macron called on voters to support candidates who are “clearly republican and democratic.” According to his recent comments, this would exclude candidates from the RN and the radical left party “La France Inspontible” (LFI).

Leading politicians from both the centre-left and the far-left camps called on their third-place candidates to withdraw from the election.

“Our guiding principle is simple and clear: not a single more vote for the Rassemblement National,” said the leader of the party “La France Inconqueror”, Jean-Luc Mélenchon.

However, the centre-right Republican Party, which split before the vote and saw some of its MPs join the RN, did not provide any guidance.

POSSIBLE PRIME MINISTER

Jordan Bardella, the 28-year-old leader of the RN party, has said he is ready to become prime minister if his party wins an absolute majority. He has ruled out trying to form a minority government, and neither Macron nor the left-wing NFP group will form an alliance with him.

“I will be a prime minister of cohabitation, respecting the Constitution and the office of the President of the Republic, but not compromising on the policies we implement,” he said.

The mood was gloomy on the Place de la République in Paris, where several thousand anti-RN demonstrators gathered for a rally of the left-wing alliance on Sunday evening.

Najiya Khaldi, a 33-year-old teacher, said she felt “disgust, sadness and fear” at the RN’s good results.

“I’m not used to demonstrating,” she said. “I think I came here to calm myself down and not feel alone.”

The market reaction to Sunday’s result was muted. The euro gained about 0.23 percent in early Asia-Pacific trading. Fiona Cincotta, senior market analyst at London’s City Index, said she was relieved that the result had brought “no surprises.”

“Le Pen’s lead was a little smaller than some polls indicated, which may have given the euro a little boost at the opening,” she said. “Now the attention turns to July 7 to see whether the second round will give an absolute majority or not. So it feels like we’re a little bit in limbo.”

COMPLEX ANALYSIS

The RN was expected to win the most seats in the National Assembly, but only one of the pollsters – Elabe – predicted the party would win an absolute majority of 289 seats in the runoff.

Experts say seat forecasts after first-round voting can be highly inaccurate, and this is especially true in this election.

No official national results were available on Sunday evening, but they were expected in the next few hours. In France, post-election polls are usually very accurate.

Voter turnout was high compared to previous parliamentary elections, highlighting the political fervour that Macron had aroused with his surprising and politically risky decision to call a parliamentary election.

At 15:00 GMT, turnout was nearly 60%, compared with 39.42% two years ago. This was the highest comparable turnout since the 1986 parliamentary election, said Mathieu Gallard, head of research at Ipsos France. It was unclear when official turnout figures would be updated.

(Additional reporting by Ardee Napolitano and Janis Laizans in Henin-Beaumont and Clotaire Achi, Imad Creidi, Lucien Libert in Paris. Writing by Gabriel Stargardter. Editing by Andrew Heavens, Philippa Fletcher and Frances Kerry.)