Bernard Cazeneuve takes over as French PM as Valls announces presidential bid

Socialist French Prime Minister Manuel Valls is to announce later on Monday that he will run for president in next year's election, Agence France-Presse and French television reported.

Valls' party currently polling 3rd behind Les Republicains and National Front

French Prime Minister Manuel Valls delivers a speech to announce his bid to become the Socialist presidential candidate in the 2017 presidential elections, at the town hall of Evry, south of Paris, on Monday evening. (Lionel Bonaventure/AFP/Getty Images)

French Prime Minister Manuel Valls declared on Monday that he would seek the Socialist Party's nomination for next year's presidential election and said he was quitting the government to focus on campaigning.

Although opinion polls bill Valls as the favourite for the Socialists' ticket, they also forecast that neither he nor any other left-wing candidate will win the election, rather that conservative candidate François Fillon will beat far-right National Front leader Marine Le Pen in a run-off.

"We're told the left does not stand a chance, but nothing's set in stone," Valls said to applause from supporters in his fiefdom of Evry, the gritty southern suburb of Paris where he was mayor for over a decade.

"I want us to lead the left to victory!" the 54-year-old said, urging his much-divided camp to unite.

Fillon, a 62-year-old former prime minister, secured a resounding win to become the presidential candidate of the centre-right Les Republicains party.

France's presidential election takes place in two rounds next April and May.

Valls has long been seen as a presidential candidate, and his status as the Socialists' likely choice for 2017 was cemented further last week after François Hollande's shock announcement that he would not seek a second term. Hollande is the first leader since France's Fifth Republic was created in 1958 not to seek a second mandate.

The Socialists face a tough battle over whether they should be more centrist or veer more to the left to try and regain the popularity they have lost since Hollande was elected in 2012.

Manuel Valls thanks supporters after delivering a speech to announce his bid to become the Socialist presidential candidate in the 2017 presidential elections. (Lionel Bonaventure/AFP/Getty Images)

Focus on jobs, security

Valls is a law-and-order hardliner whose business-friendly economic stance face attack from his rivals from the traditional left of the party in campaigning ahead of the Socialist-led left-wing primaries in late January.

Valls will also have to extricate himself from Hollande's turbulent five years at the helm of the euro zone's number two economy if he is to persuade voters he is the best candidate to heal the party's rifts.

"We must unite: My candidacy is one of conciliation, of reconciliation," he said.

Valls said his resignation as prime minister would take effect immediately.

Valls said reducing high unemployment would be his priority and he pledged to lower taxes for the poorest and for the middle-class, if elected. He also promised to protect France's social security system.

He faces a fight for the Socialist nomination. There are now eight candidates, with Valls' chief rival being former economy minister Arnaud Montebourg, who is popular among the traditional left.

Bernard Cazeneuve, seen in 2015, will serve as prime minister in the Hollande government. (Etienne Laurent/EPA)

Bernard Cazeneuve, currently French interior minister, will replace Valls as the country's new prime minister, President Hollande's office said early Tuesday. "

"He's a strong personality, with experience of state affairs," said a source in the president's entourage, commenting on Cazeneuve's appointment.