The French Socialist Party has elected Francois Hollande as its candidate in next year's presidential vote.
He will challenge the current President Nicolas Sarkozy. Mr Hollande's rival, Martine Aubry, conceded victory in today's national primary run-off after he took a lead of 57% to 43% in the count.
It's the first time voters in France have taken part in an American-style primary.
Conceding defeat, Ms Aubry called for unity behind Mr Hollande.
“I will invest all my strength and energy to ensure that he (Hollande) is the president of France seven months from now," she said.
Mr Hollande is regarded as a moderate within the Socialist Party and is little known beyond France.
Critics said Mr Hollande, who has never held a national government post, compared poorly to Aubry, one-time labour minister, architect of France's 35-hour week and daughter of the former European Commission President Jacques Delors.
The polls suggest French voters are ready to put the left back in power after five years of conservative Sarkozy, who is unpopular but widely expected to seek another five-year term.
The left's runaway favourite to become president had been former International Monetary Fund chief Dominique Strauss-Kahn but his IMF career and presidential hopes were halted when he was arrested in New York in May on charges of sexually assaulting a hotel maid. The charges have since been dropped.
More than 2.6 million people voted in the first-round last Sunday, when anti-globalisation hardliner Arnaud Montebourg scored a surprise 17%.
Mr Sarkozy, who took power in 2007 after 12 years of Jacques Chirac, has yet to declare a re-election bid.
Opinion polls show him trailing either Hollande or Aubry in the election which takes place in two rounds on 22 April and 6 May, followed weeks later by a parliamentary election.
