Manuel Valls, who quit as Socialist prime minister a month ago to prepare a campaign for this year's presidential election, remains the clear favourite to win the left-wing primaries later this month, an opinion poll published today showed.

Valls is seen coming top in the January 22 first round vote with 43 per cent, ahead of second placed Arnaud Montebourg, the former economy minister, who is set to win 25 percent, and third-placed Benoit Hamon on 22 per cent, the poll by Harris Interactive for France Televisions showed.

He would go on to win the left-wing ticket by beating either of these two opponents in a run-off second round vote on Jan 29, with between 55 and 57 per cent of the vote, according to the poll - a similar outcome to other polls conducted in December.

Opinion polls of voting intentions for the presidential election itself show Valls - closely associated with the record of unpopular outgoing President Francois Hollande - with very little chance of winning the presidency.

He is seen in a distant fifth place, eliminated after the April 23 first round. The May 7 second-round run-off is likely to be won by conservative Francois Fillon over the far-right's Marine Le Pen, those polls show.