PARIS • France's presidential race started in earnest yesterday as seven rightwing candidates including former president Nicolas Sarkozy were confirmed to contest a November primary, with the nominee seen as the likely winner of next year's election.

The stakes are high, with polls showing the winner of a duel between the two leading candidates from the Republican party, Mr Sarkozy and former prime minister Alain Juppe, would be the clear favourite to prevail in May.

Following the confirmation of the candidates by election officials, two rounds of voting will be held on Nov 20 and 27 to select a rightwing nominee.

National identity and Islam have emerged as key themes in their contest, which has echoes of US Republican nominee Donald Trump's campaign for the White House.

Mr Sarkozy is a brash rightwinger and a divisive figure in French politics, while the experienced Mr Juppe, now mayor of Bordeaux, has styled himself as a unifying force.

"The candidates all agree on the economy," said political scientist Thomas Guenole, the author of a book on Mr Sarkozy's comeback, referring to their consensus on cutting taxes and relaxing France's 35-hour work week.

"The only issues on which they create divisions are the four Is: Islam, identity, immigration, insecurity," he said.

President Francois Hollande has yet to confirm if he will stand for re-election as the Socialists' candidate in a run that would defy his historically low approval ratings.

On the far-right, the National Front is set for battle, with its leader Marine Le Pen widely forecast to successfully negotiate the first round of national voting in April and then lose in the second round against a mainstream candidate.

Mr Juppe, 71, France's most popular politician, is favoured to emerge victorious, but Mr Sarkozy is closing the gap with hardline proposals designed to woo voters reeling from a string of militant attacks.

The 61-year-old Mr Sarkozy, who led France from 2007 to 2012, has vowed a "merciless" fight against the Islamist extremists who have killed 238 people nationwide since January last year.

Saying that French identity is under attack, he has declared war on the Islamic burkini swimsuit, the wearing of the Muslim headscarf in universities and other practices he sees as "un-French".

"If you want to become French, you speak French, you live like the French. We will no longer settle for integration that does not work, we will require assimilation," he told a rally on Monday.

Mr Juppe, a moderate who served two years as premier under president Jacques Chirac and was foreign minister under Mr Sarkozy, has taken the opposite approach.

Accusing Mr Sarkozy of "pouring fuel on the fire" with his calls for a state ban on the burkini, Mr Juppe has tried to sell voters on what he sees as a "happy", secure French identity.

Vowing to knit together a fractured nation, Mr Juppe has promised to "reach out" to the vast majority of Muslims who adhere to France's secular values.

Mr Juppe has undergone a radical makeover from the grey technocrat who spent years in the political desert over a fake job scandal at Paris City Hall in the 1990s to benign elder statesman.

He has repeatedly made overtures to centrists as well as leftists, who can vote in the primary if they pay €2 and sign a charter declaring they adhere to centrist or conservative values.

According to Mr Jerome Fourquet of the pollsters Ifop, the choice between "a war chief and someone who is wiser, more reassuring and brings people together" will come down to whether the French believe the country is, as Mr Sarkozy says, "at war".

A Harris Interactive poll last week predicted a tie between the two in the first round of the primary, with Mr Juppe going on to win the run-off a week later by 52 per cent to Mr Sarkozy's 48 per cent.

Their rivals are Mr Sarkozy's former premier Francois Fillon, his former agriculture minister Bruno Le Maire, Ms Nathalie Kosciusko- Morizet, Mr Jean-Frederic Poisson and Mr Jean-Francois Cope.

For Mr Fourquet, "the ideological centre of gravity of the right is closer to Nicolas Sarkozy's positions than those of Alain Juppe".

But Mr Sarkozy is also hobbled by his legacy, seen as underwhelming economically, and is disliked by a majority of French people.

Mr Fourquet predicted a possible bid by leftist and centrist voters to block Mr Sarkozy's return by voting for Mr Juppe in the primary.

AGENCE FRANCE-PRESSE