PARIS • French Socialists were yesterday due to choose their candidate for this year's presidential election, in a run-off pitting pro-business former premier Manuel Valls against hard-left lawmaker Benoit Hamon.

Mr Hamon, who is often compared with British Labour leader Jeremy Corbyn, is favoured to beat Mr Valls in the primary's head-to-head vote but has little chance of winning the presidency after five years of unpopular Socialist rule.

Opinion polls have shown neither man would garner enough support to reach the election's run-off in May, and were likely to come in fifth place in the first round behind centrist Emmanuel Macron and left-winger Jean-Luc Melenchon.

The two front runners are conservative Francois Fillon, currently embroiled in a scandal over his wife's work as his parliamentary assistant, and far-right leader Marine Le Pen.

Although the Socialist candidate has little chance of succeeding President Francois Hollande at the Elysee Palace, the winner of the vote would help decide the fortune of other candidates.

A victory by Mr Hamon, who wants to give a "universal income" to all citizens at a cost of €350 billion (S$536 billion) and tax robots, would boost Mr Macron's chances by pushing Mr Valls' centre-left supporters into the former investment banker's arms.

Mr Hamon, a former education minister, was kicked out of Mr Valls' government in 2014 for differences on economic policy.

Mr Macron was Mr Valls' economy minister until he quit last year to launch his presidential campaign. But he was not a party member and has spurned the Socialist primaries that Mr Valls and Mr Hamon are contesting, having launched his own centrist political movement. The latest polls show him breathing down the necks of Mr Fillon and Ms Le Pen.

This refusal of the most pro-business wing of the party to rally behind a more radical leftist could hasten a break-up of the Socialist party, for decades one of the main political forces in France, analysts said.

REUTERS