By William Horobin

PARIS -- Former President Nicolas Sarkozy was knocked out of the first round of the French conservatives' primary, marking a significant upset in the race to become France's next president.

Mr. Sarkozy, who centered his campaign on pledges for hard-line security measures and a clampdown on immigration, was hobbled by a late, surprise surge in support for his former prime minister, François Fillon, who ran on a pledge to deliver a shock to the French economy with deep spending cuts and labor overhauls.

Results from 7,365 of the 10,228 polling stations across the country showed Mr. Fillon won 43.7% of the early votes, ahead of the 27.8% received by Bordeaux Mayor Alain Juppé, who recent polls showed had been the favorite to win the primary. Mr. Sarkozy, by contrast, won just 21.7% of votes.

The former French leader's elimination in the first round upends a conservative primary that is set to have sweeping consequences in France. Polls show the winner next Sunday would be best placed to win the presidential election in May against the far-right National Front's Marine Le Pen.

Mr. Fillon and Mr. Juppé will now advance to a runoff next Sunday. Mr. Sarkozy, who conceded defeat late Sunday, said he would throw his support behind Mr. Fillon. "It is time for me to attempt a life with more private passion and less public passion," Mr. Sarkozy said.

Until last week, polls had shown Mr. Sarkozy would easily reach the second round and go head-to-head with Mr. Juppé in a second-round race centered on questions of French identity and security in the aftermath of a string of terror attacks in France.

Mr. Sarkozy shifted to the right in his campaign in a bid to reach out to Ms. Le Pen's supporters. He advocated suspending the right of immigrants to bring their families to France and locking up people of watch lists deemed dangerous by intelligence services. Mr. Juppé, meanwhile, tacked in the other direction, centering his campaign on a pledge to reforge a "happy identity" that respects differences and overcomes tensions in French society.

Mr. Fillon's progression to the second round significantly changes the dynamic of the campaign.

The 62-year-old Mr. Fillon, who served as prime minister between 2007 and 2012, has said the malaise behind all of France's woes is economic and financial. The most pro-business of the candidates, he proposes scrapping swaths of France's labor code, scrapping the 35-hour workweek, taking power from labor unions and increasing sales taxes on consumers to help fund tax breaks for business.

He has also advocated toughspending cuts, rooted in a plan to abolish around half a million public-sector jobs. "With our mountain of debt, we are sliding toward bankruptcy," Mr. Fillon said in his final campaign speech on Friday.

Mr. Juppé has outlined a milder treatment for France's economic problems. If president, he has said he wouldn't raise sales taxes so sharply and would cut fewer public-sector jobs.

Mr. Sarkozy's defeat in the first stage of the primary is a major blow for former president after a carefully orchestrated return to the front line of French politics. The 61-year-old took control of his divided center-right party in 2014 after having sworn off politics following his defeat to Mr. Hollande in 2012. He then rebranded the party Les Républicains, appointing loyal allies to senior positions before announcing his presidential candidacy in August this year.

Write to William Horobin at William.Horobin@wsj.com

(END) Dow Jones NewswiresNovember 20, 2016 17:12 ET (22:12 GMT)

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