PARIS (Reuters) - Manuel Valls, who launched a bid for France's presidential election on Monday, would not gather enough support to go through to its second round, according to an opinion poll published on Wednesday (Dec 7).

Valls, President Francois Hollande's prime minister since the spring of 2014, quit this week to run for president after Hollande himself decided against seeking a second term.

If Valls were to win the Socialist Party's nomination in a primary contest in January, he would gather only 13 percent of votes in the first round of the presidential election, due to take place on April 23, the BVA-Salesforce poll showed.

He would do better if his only major competitor on the left was firebrand Jean-Luc Melenchon and if his ex-economy minister Emmanuel Macron, who has said he will run, did not eventually take part in the presidential ballot.

But the 21 percent Valls would get in that scenario would still not be enough for him to qualify for the second round.

"The second round appears totally out of reach of a three-headed left, but even with just two heads, Manuel Valls and Jean-Luc Melenchon, the second round is not reachable either," BVA's Erwan Lestrohan told Reuters.

The survey for telecom company Orange and regional newspapers confirmed previous polls which showed that conservative candidate Francois Fillon and the far-right National Front's Marine Le Pen would both qualify for the second round, whoever was running for the left.

It forecast that Fillon would beat Le Pen in the two-way run-off, with 67 per cent of votes to her 33 per cent.

The pollsters questioned 934 people online between Dec 2 and Dec 4.