Fillon the Conservative Pick for French Presidential Election

French politician Francois Fillon, member of the conservative Les Republicains political party, prepares to cast his ballot during the second round of the French center-right presidential primary election in Paris, France, November 27. Eric Feferberg/Reuters

Francois Fillon, a socially conservative free-marketeer, is to be the presidential candidate of the French center-right and likely main challenger to far-right leader Marine Le Pen in next year's election, first partial results of a primaries' second-round vote showed on Sunday.

With votes from over a third of 10,228 polling stations counted, Fillon, who went into Sunday's second-round run-off as favorite, had won 68.6 percent of the vote in the head-to-head run-off compared with 31.4 percent for his rival, another ex-prime minister, Alain Juppe.

All eyes now turn to the ruling Socialist party and to whether the deeply unpopular President Francois Hollande will decide to run for the left-wing ticket in his party's primaries in January, amid signs that his prime minister, Manuel Valls, is considering a bid of his own.

Opinion polls suggest that no left-wing candidate would make the run-off second round of the presidential election itself next May, leaving Fillon a clear run at the anti-EU, anti-immigration Le Pen that the surveys expect him to win.

Polls have nevertheless recently proven out of step with the voting patterns that saw Britain vote to leave the EU and Americans elect Donald Trump as president.

Next year's French presidentials are shaping up to be another test of anti-establishment anger in Western countries.

Fillon, 62, came from behind in opinion polls over the past two weeks. In last week's first round Les Republicains party primary he knocked out former president Nicolas Sarkozy, under whom he served as prime minister from 2007 to 2012, and pushed Juppe into second place.

A racing car enthusiast who lives in a Loire valley chateau, Fillon promises radical reforms to France's regulation-encumbered economy, vowing to roll back the state and slash government's bloated costs.

The Socialist primaries are due to take place in January. Hollande has two weeks in which to decide whether to take part in these primaries and run for re-election.

The conservative primaries' win for Fillon and his hardline economic platform give the 62-year-old Hollande a target to attack and could convince him to make a bid for a second five-year mandate against the odds.