PARIS — Popular French economist Gabriel Zucman says French Prime Minister Sébastien Lecornu made a fatal mistake by not embracing his eponymous “Zucman tax.”

Zucman told POLITICO in an interview that both Lecornu, whose government resigned Monday morning, and his two immediate predecessors had not taken the proposal seriously.

“The executive has so far remained completely deaf to both parliamentary work and popular democratic demands,” he said. “They didn’t try to have a real dialogue with the opposition on this.” He added that ruling out higher taxes is what “blocks the country, wastes time.”

Zucman has become a household name in France thanks to his tax, which calls for households worth more than €100 million to pay an annual tax of at least 2 percent of the value of all their assets.

The measure seems extremely popular with voters. A poll commissioned by the Socialist Party, which supports the tax and had pushed Lecornu to adopt it, showed that 86 percent of respondents viewed the Zucman tax favorably.

“There is a very strong demand among the population for greater tax fairness and better taxation of the ultrarich,” Zucman said.

Politically, however, the Zucman tax remains a lightning rod given questions about how much revenue it would bring in, its legality and whether it would lead to capital flight. In an interview with Le Parisien, Lecornu said he was not in favor of the tax measure because it would apply to professional assets. But he did acknowledge the widespread support for a more equitable tax regime.

The conservative Les Républicains, a coalition partner in previous minority governments, opposed it and wanted assurances from Lecornu that he would rule out implementing such a tax as a condition for supporting his government.

Zucman’s pro-tax crusade earned him personal attacks by heavyweights including French billionaire Bernard Arnault.

“The very wealthy individuals affected by this measure, and the media outlets they own, have spoken out very vehemently on the subject in an attempt to discourage the government from engaging in any form of reflection or discussion,” Zucman said.

However, the 38-year-old, who teaches at the Paris School of Economics as well as the University of California, Berkeley, is grateful that the political and media attention has contributed to “a better understanding” of the issues surrounding taxation.

“I am happy as the level of the debate has improved,” he said.

It’s not too late

Lecornu’s resignation has plunged the country into deep political and financial uncertainty. Borrowing costs rose on the news while the euro fell by over half a cent against the dollar, a rare instance of domestic political upheaval having effects beyond France’s borders.

Zucman sees the problem as something that can be fixed rather than an existential threat that could drag down the entire eurozone, thanks in part to the French public’s high level of private savings and the assets they already own.

“We should not dramatize,” Zucman said. “France is not at the mercy of its international creditors.”

Taxing the private assets of the ultrarich, Zucman contends, would help France to overcome its budget crisis.

“It is a problem that financially has a solution and this solution belongs to the French,” he said.