JPMorgan CEO Jamie Dimon and other major bank executives warned lawmakers on Wednesday that proposed capital hikes and new regulations by U.S. bank regulators could negatively impact lending, capital markets, and the broader economy.

The banking industry has been actively opposing the “Basel endgame” proposal, which aims to revamp how banks calculate their loss-absorbing capital. Simultaneously, regulators are introducing fair lending and fee cap regulations, among other rules.

In a hearing, CEOs, including Dimon, Bank of America’s Brian Moynihan, Wells Fargo’s Charles Scharf, Goldman Sachs’ David Solomon, Morgan Stanley’s James Gorman, State Street (NYSE:STT)’s Ronald O’Hanley, and BNY Mellon (NYSE:BK)’s Robin Vince, expressed concerns about the potential consequences of the proposed rules. They argued that the changes could stifle lending, particularly affecting small businesses and consumers.

Dimon, in his prepared testimony, stated, “If enacted as drafted, this proposal will fundamentally alter the U.S. economy in ways that the Federal Reserve has not studied or contemplated.”

Senator Sherrod Brown, who chairs the Committee, criticized the banks for aggressive lobbying against the rules, accusing them of overstating the potential adverse impacts to preserve their profit margins.

While CEOs may find support among Republicans who generally oppose strict regulations, they need to persuade skeptical Democratic lawmakers about the soundness of the banking sector. Senator Tim Scott, the panel’s top Republican, echoed concerns about the proposed rules having a “devastating impact” on small businesses.

These hearings, a routine occurrence since the 2007-09 financial crisis, rarely result in immediate legislation but have historically influenced banks to make changes in response to regulatory concerns.