Paris, Jan 30 (IANS): Former French Prime Minister Benoit Hamon won the Socialist Party's presidential primary runoff with 58.7 per cent of the votes.

According to preliminary results, his challenger in the runoff on Sunday, Manuel Valls, also a former Prime Minister, obtained 41.4 percent, Efe news reported.

Election organisers announced the results with 60 per cent of the votes counted. A total of 2 million ballots reportedly were cast to determine the Socialist Party's presidential nominee in the April 23 national election.

Some 4 million people voted in the primaries for the French right.

Meanwhile, Valls acknowledged that Hamon "clearly won" the primary runoff and will be the presidential candidate of the Socialist "political family". He went on to "warmly congratulate" his rival.

The result constitutes a victory for the candidate representing the more leftist wing of the Socialist Party, the faction critical of current President Francois Hollande, whom Valls has served as Premier and later Interior Minister.

Leading in the voter surveys at present is ultrarightist Marine Le Pen and conservative Francois Fillon, but also ahead of Hamon in the polls is former Economy Minister Emmanuel Macron and leftist radical Jean-Luc Melenchon.