In the latest back-and-forth between federal regulators and their opponents over supervision of nonbank fintech companies, Acting Comptroller of the Currency Brian Brooks defended his agency’s efforts to develop a national regulatory scheme for fintech companies at a conference last week.

According to Banking Dive, Brooks told the gathering at Lendit Fintech that “unbundling” – the practice of consumers getting their financial services from companies that are not traditional financial institutions – was not going away.

“Customers want what they want,” he said. “The question is, is our platform flexible enough to accommodate that? And I think it has to be.”

Brooks said in an interview this summer that the Office of the Comptroller of the Currency (OCC) was preparing to launch the first version of a charter for nonbank payments companies, which he called a “national version of a state money transmission license.”

Trade organizations representing traditional financial institutions have rejected that idea. Last week, the  American Bankers Association, the Bank Policy Institute, the Independent Community Bankers of America and The Clearing House released a letter to Congress stating their objection to the proposed payments charter.

“A payments charter for non-banks firms raises a number of regulatory concerns—such as the continuation of the long-standing principles of the separation of banking and commerce, application of  traditional banking statutes and regulations governing safety and soundness and consumer protection, and, most significantly, the potential introduction of systemic risk into the payments system,” the letter said.

State regulators also oppose the idea of national charters for nonbank companies. The New York Division of Financial Services is challenging the OCC with a lawsuit over its proposed fintech charter. The Conference of State Bank Supervisors has issued comments in support of that lawsuit, saying, “State regulators will fight any effort to preempt state laws that protect consumers and ensure a safe and sound financial system.”