WASHINGTON — When federal financial regulators next gather to compare notes and coordinate plans, one of the requirements of a banking law intended to prevent the next financial crisis, 5 of the 10 seats at the table will most likely be empty or filled by caretakers.

The Obama administration has not announced nominees for several positions that Congress created last summer, nor has it nominated new heads for three agencies, including for an imminent vacancy at the Federal Deposit Insurance Corporation.

As a result, temporary leaders tapped by the president increasingly are responsible for the vast overhaul of financial regulations, raising concerns that their decisions will prove more vulnerable to political pressure than permanent leaders insulated by Senate confirmation to a fixed term.

“I look back on my last five years and all the tough decisions I had to make, and if I’d been in an acting capacity, it would have been very inhibiting to me in making some of the tough decisions I had to do,” Sheila C. Bair, who in early June will complete her term as chairwoman of the F.D.I.C., told the Senate Banking Committee on Thursday.