PARIS • The pledges came in quick succession.

Mr Francois-Henri Pinault, France's second-richest man, put up an eye-popping €100 million (S$153 million) to rebuild Notre-Dame, just as firefighters were dousing the last flames at the cathedral on Tuesday morning.

Not to be outdone, Mr Bernard Arnault, France's wealthiest scion and a fierce rival to Mr Pinault and to his father, Mr Francois Pinault, upped the ante with a €200 million gift a few hours later.

Another wealthy donor, global cosmetics giant L'Oreal, stepped up. The company's heirs, the Bettencourt-Meyers, announced a €200 million donation for Notre-Dame on Tuesday through the Bettencourt Schueller Foundation.

By Wednesday, the government had welcomed some €850 million offered in the patriotic name of salvaging the cultural treasure, as money from wealthy French families, French companies and international corporations poured in.

But the spectacle of billionaires trying to one-up one another quickly intensified resentment over inequality that has flared during the "yellow vest" movement, just as President Emmanuel Macron was looking to transform the calamity into a new era of national unity.

There were accusations that the wildly rich were trying to wash their reputations during a time of national tragedy.

"Can you imagine, 100 million, 200 million in one click! It shows the inequalities in this country," said Mr Philippe Martinez, head of the militant CGT labour union.

"If they're able to give dozens of millions to rebuild Notre-Dame, they should stop telling us that there is no money to pay for social inequalities," he added.

Mr Ollivier Pourriol, a French philosopher and novelist, summed up the sentiment more drolly. "Victor Hugo thanks all the generous donors ready to save Notre-Dame and proposes that they do the same thing with Les Miserables," he wrote on Twitter, referring to another of Hugo's famous novels, about the lives of the poor.

Ms Manon Aubry, a senior figure in France Insoumise, the main radical left party, called the funding an "exercise in public relations".

She said the donors' list "looks like the rankings of companies and people located in tax havens".

The bickering was about as far as possible to imagine from the image of a united France the President painted when he gave a national address on Tuesday. Mr Macron said "it is up to us to transform this catastrophe" into a moment to become "better than what we are".

The firestorm began when Mr Jean-Jacques Aillagon, a former culture minister and now adviser to Mr Francois Pinault, went on Twitter, after Mr Francois-Henri Pinault announced his gift on Tuesday, to suggest that corporate contributions to Notre-Dame's restoration be given a 90 per cent tax deduction, rather than the 60 per cent that corporations normally get for charitable contributions.

"That's when the whole thing exploded," said Mr Pierre Haski, a commentator for France-Inter, the public radio station. "That produced outrage, that this act of generosity turns into fiscal advantage."

The reaction was so intense that Mr Aillagon went on radio on Wednesday morning to retract his suggestion. The Pinault family then announced that they would seek no tax deduction at all for the gift.

"It was very revealing about the sensitivity of the whole issue," Mr Haski said, coming in the midst of a great national debate about the yellow vests and their protests against inequality and fiscal privileges.

When it looked like other wealthy donors might be able to benefit from a generous tax perk for their largesse, Prime Minister Edouard Philippe sought to douse tensions at a news conference on Wednesday.

"We must be delighted that very low-income individuals, very wealthy individuals as well as companies want to participate in the effort to rebuild a cathedral that is at the heart of our history," he said.

In general, many are relieved that Notre-Dame still stands, and if there is now €1 billion to reconstruct it without calling too deeply on an already-stretched national budget, that may be enough. But taxes have been one of the pressing issues in the yellow-vest movement and the one that Mr Macron has had most trouble diffusing.

The companies contributing are among the largest in France and account for tens of thousands of jobs at home and abroad in the luxury, energy and construction industries.

But for many, they are also symbols of an untouchable class of super-rich who keep getting richer, thanks to a host of fiscal advantages.