Mme Royal has been an ‘ambassador’ for the Polar Regions, dealing with the various environmental threats to those areas, with €100,000 expenses a year.
It is now alleged she has been using – or misusing – that money to further her personal political aims, and there are demands for a full investigation and prosecution. Mme Royal denies everything.
Her declared rival, Marine Le Pen, faces accusations of mis-spending the money of her former party, the Front National. So much for the great issues of the 2022 campaign.
With memories still fresh of how a front-runner for 2017, François Fillon, was cut off at the knees over allegations that he misused public funds as prime minister to provide cash for his wife and children, the expenses-fiddling weapon is a potent one; and with the Macroniste establishment deploying it against Mme Royal, someone is getting worried.
With Mme Royal coming in from the left, and Mme Le Pen in the race early, not least to raise her party’s profile before March’s municipal elections, things take on an even more threatening aspect for a beleaguered incumbent whose retreat on pensionable age – though not on pension reform – has done little to assert his authority or improve his credibility.
Because she lost the 2007 election to Nicolas Sarkozy by what to the French was the vast margin of six points – 47 to 53, a respectable result in any other democracy – there has been a tendency to dismiss Mme Royal.
But fighting a losing campaign is a better experience than fighting no campaign at all, as Mme Le Pen will testify, and she is likely to be a more formidable opponent as a result.
But she will be a more formidable opponent still because of all the water under the bridge since she last stood – because the whole landscape of French politics has changed, as have the priorities with which a president must deal.
In 2012 the father of Mme Royal’s children, François Hollande, picked up the baton of socialism that she had dropped after losing to Mr Sarkozy.
As history relates, he made such an appalling job of it that not only did his political career evaporate, so too did his party.
The Parti Socialiste is now little more than a fringe group, like La France Insoumise, the remnants of the hard-line socialist party that helped divide the left before the last election.
Now, too many people who would once have voted for a leftist candidate in an attempt to secure social justice increasingly channel their anger into the Rassemblement National, led by Mme Le Pen and busily trying to shed its image as the inheritors of a fascist party; or they become involved with the extra-parliamentary activity of the gilets jaunes, in some sort of nascent quasi-anarchistic grouping with the strikers who have done so much in recent weeks to cripple France.
Mme Royal’s ‘structure’ for 2022 is a group calling itself ‘Désirs de France, avenir de la planete’.
That tells us two things about her: first, that even if in her heart of hearts she has not rejected some of the tenets of the socialist creed with which she grew up and that shaped her persona as a politician, she knows there is as much chance of a straightforward PS candidate winning the next election as there is of Notre Dame being rebuilt in a day.
So it is no longer the old creed that people of the left such as Mme Royal use as the basis of their request for votes, which brings us on to the second point.
A campaign that starts from environmental concerns but leads on to other considerations not only demonstrates a supposedly thoughtful commitment to future sustainability, but also allows the drawing in to the Royal fold of people who might not have thought of themselves as socialists – which is rather similar to what the ex-socialist President Macron did to get his majority last time.
And, at the same time, to salve those socialist credentials, Mme Royal can use her campaign to bash carbon-emitting, fossil-fuel obsessed capitalists, which never goes down badly in a France that understands too little the link between successful enterprise and the provision of funds through the tax system for better public services.
A poll taken in January showed that Mr Macron is on course to beat Mme Le Pen yet again in 2022.
Mme Le Pen was already worried about her place as France’s chief populist, and seems to have got her show on the road so early also to get in ahead of any rogue gilet jaune who might decide to steal her clothes.
But the system being against her – the best-of-two final round always ensures that the hard-right candidate loses because most of the supporters of the eliminated candidates who bother to vote gang up on her – is now complicated by the potential campaign of Mme Royal.
If her environmentalist message gains traction, and gains supporters, she could end up in the second round with Mr Macron, which would provide a real contest. She could even supplant him, and find herself taking on Mme Le Pen in the second round, in which case Mme Royal, phoenix-like after her struggle in 2007, could rise from the ashes.
That, of course, would depend on Les Républicains not reviving from their present moribund state and presenting a serious conservative option for the French electorate.
We shall have a better idea of the prospects of that after March’s municipal elections, but it might be best not to hold one’s breath.
Simon Heffer, the renowned political commentator and historian, turns his gaze to French politics. Simon Heffer is also a columnist for the Daily and Sunday Telegraphs