Can Francois Fillon survive to contest French election?
Francois Fillon's chances of political survival are hanging on a thread, and if you want to know why just listen to French talk radio.
This morning on RMC when broadcaster Jean-Jacques Bourdin took calls about Penelopegate, the mood was angry.
Caller after caller pointed up the vast difference in their own salary, and the money - up to €10,000 ($10,800; £8,540) a month - which Penelope Fillon took as her husband's parliamentary assistant. "And I actually work!" said one.
It is becoming obvious that - whether or not Francois Fillon makes a successful legal case to fend off charges of corruption - the real issue is elsewhere.
It lies in the vast gulf that the affair appears to expose yet again between a cosseted political class - for whom the acquisition of material comfort seems part of the natural order - and the rest.
Bringing down the favourite
As the centrist political leader Francois Bayrou put it: "It seems that on one side there are privileges and on the other side there are sacrifices. And as the sacrifices get bigger, so do the privileges."
So what started last week as a page three article in Le Canard Enchaine (it was not even on the front) now has a serious chance of bringing down the man seen as favourite to be the next French head of state.
Events are accelerating. On Tuesday, financial police searched offices in the National Assembly, looking for Penelope Fillon's work contracts - that may or may not have existed.
BFMTV reported that she told investigators she had no memory of signing them.
Next, Francois Fillon's replacement as MP Marc Joulaud - who kept Penelope on as a paid assistant after Mr Fillon entered the government in 2002 - is also being questioned.
In the other arm of their investigation, police have also spoken to the billionaire Marc Ladreit de Lacharriere over the €100,000 that was paid to Penelope Fillon for apparently doing no more than write two short book reviews.
It has also been established that Francois Fillon ended the arrangement with his wife in December 2013 - just a few weeks before new parliamentary rules would have obliged him to make public the names of his assistants.
'Cut off the gangrene'
Mr Fillon continues to counter attack. He insists his wife's employment was above board, and that the charges against him are part of a "institutional coup d'etat from the left".
But in the Republican Party, what was unthinkable a few days ago is now outwardly mooted: that Francois Fillon may need to step down and be replaced.
"There is a growing feeling that the party needs to cut off the gangrene before it spreads," the political columnist at Les Echos newspaper, Cecile Cornudet, told me.
Because the damage is already visible. Today Les Echos has an opinion poll which for the first time shows Francois Fillon failing to make it to round two of the presidential election in April-May.
The political advantage falls to two people: Marine Le Pen for the Front National, of course, for whom the scandal is more grist to the populist mill.
But more importantly perhaps, the main beneficiary is the modernising former minister Emmanuel Macron.
In two different scenarios posited by Les Echos (the presence or absence of another centrist candidate Francois Bayrou) Emmanuel Macron knocks Mr Fillon into third place.
In other words if Mr Fillon stays in the race, Mr Macron is the likely second-round candidate against Marine Le Pen. Therefore Mr Macron is the likely next president.
Republican party chiefs are urgently processing this. Their options are hard to discern.
A second primary is unlikely because it would be too complicated. So a new method for choosing a replacement candidate would have to be devised. Many eyes are turning to Alain Juppe, the runner-up in November's primary.
Last week Mr Juppe said there was no way he would let himself be considered again as a candidate - but that was then.
"What is striking to me is how little help there is being directed at Fillon from his fellows in the party," says Cecile Cornudet. "It doesn't look good for him."
Former President Nicolas Sarkozy is no doubt watching closely, and other senior Republican figures are also being mentioned, such as Francois Baroin, Laurent Wauquiez and Xavier Bertrand.
Interestingly the domain names Baroin2017.fr, Wauquiez2017.fr and Bertrand2017.fr have all just been registered at a leading French internet host.