Paris: One of the first questions for the French right’s presidential candidate, Francois Fillon, is whether he can act as a rampart against the far-right Front National.

Polls currently suggest the French presidential election final round in May will be a battle between the newly chosen Republican party candidate and the Front National leader, Marine Le Pen.

The Front National has reason to fear Fillon. His traditionalist and socially conservative line on family values and “the Christian roots of France”, his emphasis on French national identity, “sovereignty” and “patriotism”, his hard line on immigration and Islam as well as a pro-Putin foreign agenda against “American imperialism” all overlap with some of Le Pen’s key ideas.

This could potentially see Fillon steal some of Le Pen’s most socially conservative voters, particularly right wing elderly people, who always have a big turnout to vote but remain sceptical about the Front National.

“Fillon presents us with a strategy problem, he’s the most dangerous [candidate] for the Front National,” Marion Marechal Le Pen, the Catholic and socially conservative Front National MP and niece of Marine Le Pen, told journalists this week.

But this doesn’t mean it will be unduly easy for Fillon, a former prime minister who has spent 35 years in politics and is a figurehead of the old-school Catholic, provincial French right. Despite Fillon’s hardline right wing stances, he is not a populist.

“He’s closer to [the former British prime minister] David Cameron than [the Ukip leader] Nigel Farage,” said Jean-Yves Camus, an expert on the French far right.

This leaves Le Pen a wide margin in which to go for Fillon’s jugular as she fights a campaign centred on “the people versus the elite”. The Front National has already begun attacking Fillon as a snobbish, political has-been.

It argues that Fillon, as Nicolas Sarkozy’s prime minister, was responsible for the failures of the Sarkozy era and cares more about the rich, globalised elite than the working class who have faced decades of mass unemployment.

The battle will largely focus on economic policy. Fillon has promised a “radical shock” for France with free-market reform, major cuts to public sector jobs and reducing public spending. Le Pen claims to represent the “forgotten” French underclass and has an economic line that is essentially left wing: she is anti-globalisation and favours protectionism and state intervention. Le Pen’s campaign director, David Rachline, has called Fillon’s programme “economically insane” for wanting to slash 500,000 public sector jobs.

Le Pen’s advisers believe Fillon will struggle to appeal to the lower middle class and working class voters who are afraid of losing their jobs. The Front National has slammed Fillon as a symbol of lawless, ultra-free market, globalised capitalism. Fillon, in return, says Le Pen’s economic project is simply “a cut and paste of the extreme left”.

There are some elements about Fillon that the Front National relishes — he is loathed by the left and so in theory could have difficulty in harnessing left wing voters to fully line up behind him in final-round tactical voting against Le Pen. But there are other elements of a Fillon candidacy that will make things more complex for the far right. Against Fillon, the Front National will be forced to confront its own internal divisions.

In recent years, the party has broadened its electoral appeal by calling itself “neither left nor right”, striking a delicate balance between internal differences on whether its economic policy should be more free market and whether or not to take a more high-profile stance on the social issues that appeal to the religious right.

With Le Pen’s presidential campaign not beginning in earnest until February, and the Socialist party’s candidate undecided, analysts agree that it is too early to establish what damage Fillon could do to Le Pen.

In recent days, Fillon has been fiercely outspoken against what he calls the “extremism” of the Front National. But the left has not forgiven him for a comment in 2013 when he was asked who he would hypothetically vote for in a runoff that pitted the Socialists against the Front National. He replied that he would vote for whichever was “the less sectarian”, implying that the Socialist party was on a parallel with the far right.