A BARNACLE has nothing on François Fillon. Neither scandals nor broken promises nor the defection of allies can prise the Republican candidate from his presidential campaign. Each week brings new details of his questionable practices as a businessman-politician. Last week a court put him under formal investigation for steering about €900,000 ($970,000) of public funds over 25 years to family members who it seems did little to earn it. Mr Fillon, despite a solemn vow to quit if this happened, decided to hang on.

In a televised debate on March 20th the candidate alluded to having made mistakes. One was surely his failure to declare gifts of nearly €50,000 since 2012 in the form of finely stitched suits from a Paris tailor. More damning was the news, leaked on March 21st, that investigators are looking into allegations of aggravated fraud and forgery. Reportedly these concern documents signed by Mr Fillon’s wife, Penelope, declaring the hours she claims to have worked.

The very next day Le Canard Enchaîné, an investigative weekly, reported that Mr Fillon had been paid $50,000 to lobby for a Lebanese billionaire, Fouad Makhzoumi, who owns a pipeline-making business. According to the paper, Mr Fillon arranged a meeting for him with Vladimir Putin in St Petersburg in June 2015 (as well as with Patrick Pouyanné, the boss of Total, a French oil company). Even if true, the reports do not directly contradict Mr Fillon’s denials that he took payments from Russia, but they would raise questions over his pro-Russian stance in foreign affairs. (In the debate, Mr Fillon likened Russia’s invasion of Crimea to the West’s support for an independent Kosovo.)

In a sideshow, France’s Socialist interior minister, Bruno Le Roux, resigned on March 21st after investigators began looking into his habit of giving his daughters well-paid jobs in parliament during their school holidays. Mr Fillon has little to fear from the Socialists anyway: polls suggest that both established parties are crumbling and may not recover. Less than a fifth of voters say they support the Republican. Even fewer back the official Socialist candidate, Benoît Hamon, in part because a yet more left-wing figure, Jean-Luc Mélenchon, is siphoning away his voters.

Even if Mr Fillon were to consider quitting, it would be too late for the Republicans to replace him. Eleven candidates have officially declared that they will stand in the first round of the election on April 23rd. Set aside a few obscure anti-capitalists and several self-promoting Gaullists and independents, and the race looks ever more likely to come down to two anti-establishment figures: Emmanuel Macron, a liberal ex-Socialist, and Marine Le Pen, the leader of the populist, anti-immigrant National Front.