The travails of François Fillon, the centre-right’s standard-bearer in France’s forthcoming presidential election, appear terminal. Accused of defrauding the public purse by employing his wife, Penelope, and their children in “fake” parliamentary jobs, Fillon will be formally charged by prosecutors on 15 March. Leading politicians on the right have distanced themselves from his faltering candidacy. Key campaign staff, including his chief spokesman, have quit. A national opinion poll, published on Friday, found about 70% of voters believe Fillon, who had styled himself an incorruptible Mr Clean, is wrong to stay in the race. His popularity, even with core supporters, has fallen sharply. No matter that Fillon vehemently denies any wrongdoing. His credibility is shot. In electoral terms, he is a dead man walking.

Yet the fact that Fillon, for all his woes, cannot be definitively written off says a lot about an extraordinary election that has repeatedly broken rules and set precedents. François Hollande, the desperately unpopular Socialist leader, has become the first sitting president in modern times to decline to stand for a second term. In party primaries ahead of the 23 April first-round poll, Nicolas Sarkozy, Hollande’s predecessor in the Élysée, was humiliatingly rejected by the same people who once lionised him. Other senior establishment figures, such as Manuel Valls and Alain Juppé, both former prime ministers, also fell by the wayside. This “bonfire of the elites”, as the Economist has dubbed it, reflects, in turn, an angry, insurrectionary public mood that is also evident across much of Europe.

Fillon’s troubles have had two principal knock-on effects. One is the boost given to the independent campaign waged by the supposed outsider, Emmanuel Macron. Despite his background as an investment banker, a graduate of one of France’s most exclusive colleges and economy minister under Hollande, Macron has tried to define his candidacy as an anti-establishment, almost apolitical insurgency targeting the middle ground. Young (he is 39), good looking and energetic, the contrast with an increasingly haggard Fillon is striking. Continuing the precedent-setting trend, if Macron wins – and the indications are that he has a good chance – he will be the first president to win office without the backing of an established party. The fact that the Socialist candidate, Benoît Hamon, is best known, like Labour’s Jeremy Corbyn, as a backbench rebel against his own party could make Macron’s conjuring trick all the easier.

The other main effect of Fillon’s difficulties is potentially more serious. The obsessive media attention that is daily paid to the “Penelopegate” scandal has served to obscure the growing menace posed by Marine Le Pen, leader of the far-right Front National (FN). Even before Fillon’s meltdown, most polls suggested Le Pen would make it into the election’s second round run-off on 7 May. Now it seems possible, if not likely, that Le Pen will win the first-round – another first. Thanks to the disarray on the centre-right (and the centre-left), Europe’s best-known and cleverest, most insidious promoter of a racist, xenophobic, nationalist and Islamophobic agenda has become the woman to beat for the presidency of the home of the Enlightenment.

Much has been said about how the 48-year-old Le Pen, publicly rejecting her father’s neo-Nazi and antisemitic views, has reformed the FN, cleaning up its thuggish public image, dressing up its growing band of provincial councillors and mayors in suits and massaging its message to broaden the party’s appeal beyond its working-class, industrial base. To a significant degree, the strategy has worked. The FN has increasing support in the economically struggling, peripheral areas of France’s great cities, among a white bourgeoisie that feels its cultural identity is under threat and among under-25s, a majority of whom favour the FN over other parties. The fact that one in four French under-25s is unemployed is surely not unconnected.

But any passing thought that the FN has become an acceptable part of the political mainstream, any suggestion that a Le Pen presidency, like that of Donald Trump in the US, could somehow be tolerated or knocked into shape, should be utterly rejected. The FN’s often subliminal but unmistakable message is one of hate, discrimination, division and inequality. Marine Le Pen, if she had her way, would have France quit the euro and the EU. Unlike Brexit, which was a body blow, Frexit would be fatal to the European project. Le Pen would be no friend to Britain or to the family of democratic nations. Reassuringly, analysts and pollsters claim she cannot win in the second round, whoever stands against her. But as we all know to our cost, the conventional wisdom of analysts and pollsters can be badly wrong. In this era of smashed icons and discarded shibboleths, the danger is clear.

The stakes are very high. France faces daunting economic and security challenges, not least after the terrorist attacks in Nice and Paris. Its public debt is enormous. Its social fabric is fracturing. The potential of its younger generations is being squandered. And confidence in its political class is haemorrhaging. This unpredictable, taboo-shattering election still has weeks to run. More shocks and surprises are likely. One current theory is that Fillon could be replaced by Alain Juppé. But he, too, was charged with abusing public funds and convicted in 2004. Aged 71, he is 32 years older than Macron. In a neo-revolutionary year, Juppé, like Fillon, is plainly not the change the nation craves.