At a speech before a European financial services think tank, a Republican commissioner with the Securities and Exchange Commission (SEC) threw cold water on regulators’ attempts to create environmental, social, and governance (ESG) standards for public companies.

Speaking Friday in Sweden before EuroFi, Hester Peirce argued materiality-based standards—not ESG standards—best suit investors’ needs.

Peirce said ESG-specific standards “cannot help but direct the allocation of private capital, especially when they are combined with sustainable finance initiatives designed to encourage financing of favored activities and the defunding of disfavored activities.” This redirection of capital is not, she argued, meant to primarily serve investors’ needs “but rather to direct the allocation of private capital to further government ends.”

The SEC under Chair Gary Gensler has proposed multiple ESG-related rules, most notably a new climate-related disclosure mandate, another regarding human capital, and guidelines for ESG initiatives for investments. These proposals are likely to be approved by the Democrat-led SEC later this year; Peirce and fellow Republican commissioner Mark Uyeda are firmly against the rule changes.

Across the United States, backlash against ESG initiatives has swept through Republican circles like wildfire.

“This commandeering of private capital in the name of ESG causes me grave concerns,” Peirce said, later adding, “This effort—if undertaken to starve unsustainable activities of capital and flood sustainable activities with capital—necessarily entails understanding and classifying all of economic activity in terms of its effect on an increasing number of complex, sometimes mutually contradictory metrics. This task is impossible.”

She said the result of redirecting capital this way could cause a “green bubble,” where investors “pour money uncritically into green assets” until the asset bubble inevitably pops.

She also worried creating an international ESG standard would further distort the flow of private funds to favored activities and away from unfavored activities. The problems such taxonomies would create would reverberate around the world, instead of being confined to one jurisdiction, she said. The green bubble would be global, as would its collapse. An international ESG standard would also undermine national sovereignty and the rule of law, she argued.

“Collecting bushels of data to measure the unmeasurable and quantify the unquantifiable is an unreliable basis for deciding where to send capital, even if all these data create the illusion that we understand the world and how humans live and work in it,” she said.