Polls suggest a tight race to become the Republicans candidate for the French presidential election.
The race to become the conservative candidate for France's presidential election looks tighter than ever, with voting starting on the weekend and polls suggesting whoever emerges on top will make it all the way to the Elysee Palace.
Ahead of Sunday's vote, which will whittle the field down to two candidates for a second round a week later, centrist ex-prime minister Alain Juppe was holding onto a shrinking lead.
After Britain's "Brexit" vote in June and last week's election of Donald Trump as US president, the French election in the northern spring will be the next test of strength between weakened establishment political forces and rising populist insurgents.
Opinion polls have for months suggested that National Front leader Marine Le Pen will make it to the decisive runoff in May, but that Juppe would beat her if he wins the nomination of the conservative Republicans party.
His lead, however, is being eroded by two opponents- ex-president Nicolas Sarkozy and Francois Fillon, who was Sarkozy's prime minister between 2007 and 2012.
"I can sense a surprise coming," Fillon told supporters at a rally on Friday in Paris. He urged them to "shake up" the primaries, winning wide applause and shouts of "Fillon president" from a crowd of more than 3000.
Long trailing in the polls, Fillon has come from behind in the past week, making the race even harder to call. He was judged the winner of Thursday's final televised debate - which featured seven candidates in total - before the vote, an opinion poll suggested.
Anyone can vote in the primary, which makes the outcome hard to predict and opens the way for tactical action by voters.
Lack of confidence in pollsters, who failed to predict Trump's win and Britain's vote to quit the European Union, has added to the uncertainty about both the primaries and the election itself.
But Juppe was confident on Friday that no such upset will happen. "I am not Hillary Clinton," he said on public radio, "and France is not the United States".
FRENCH REPUBLICANS CANDIDATES
Nathalie Kosciusko-Morizet Alain Juppe Jean-Francois Cope Nicolas Sarkozy Jean-Frederic Poisson Bruno Le Maire Francois Fillon