A Federal Reserve governor on Thursday said the central bank should consider incorporating a planned capital surcharge into its annual “stress tests,” suggesting that a move opposed by bank executives is gaining traction at the central bank’s highest levels.

Fed Governor Lael Brainard's comments will likely cause concern on Wall Street. Bank executives oppose including the impact of the surcharge in the stress tests because such a move would likely require them to beef up their levels of capital, which serves as a cushion against losses. That in turn would likely require banks to shrink the amount of risky assets they hold or rely less on borrowed money for daily operations, changes that could hit their bottom lines.