Jessica Guynn

USA TODAY

Former French president Nicolas Sarkozy conceded defeat in Sunday's first conservative primary that chooses the nominee for next year’s presidential election, sending two former prime ministers to a runoff.

Returns showed Francois Fillon with 44% of the vote, Alain Juppe with 28% and Sarkozy at 20%, with more than 3.2 million votes counted of an estimated total over 5 million, the Associated Press reported.

Speaking from his Paris campaign headquarters, Sarkozy called on his supporters to vote for Fillon in next Sunday's runoff between the top two vote-getters.

The nationwide conservative primary is the latest global test of rising populism and anti-elite sentiment following Donald Trump's victory in the United States and Britain's Brexit vote. All three of the top candidates focused their campaigns on immigration and security.

The French election was being closely watched in Europe, where politics have been dominated by growing concern over the flood of migrants, terrorist attacks in France and militant extremism.

The winner of the runoff would likely face Marine Le Pen of the far-right National Front in the second round of the presidential election next May because of the deeply unpopular presidency of Socialist François Hollande. The Socialist Party will hold a two-round primary in January.

The outcome of Sunday's conservative primary was difficult to predict because it marked the first time conservatives have organized one in France. Nominees were previously designated by the party.

"This is something very new for the French right," historian Jean Garrigues told FRANCE 24.

Anti-immigrant and anti-Muslim sentiment in France has boosted the candidacy of Le Pen, who has been emboldened by Trump's election.

In June, voters in the United Kingdom approved a referendum for the nation to leave the European Union, known as Brexit, sending shock waves throughout Europe.