Sandy Praeger of Kansas, one of several insurance commissioners who met with Mr. Obama at the White House last week, said: “From a consumer protection standpoint, the most important thing we do is ensure the solvency of companies. We would strenuously resist not having the ability to approve rates or having the commissioners’ oversight of rates overturned.”

“You are not necessarily helping the consumer if you keep rates artificially low,” Ms. Praeger said. “What’s worse for the consumer: having a premium increase or having to pay the full amount of a medical expense because the company is out of business?”

Mr. Obama has cited his proposal for a Health Insurance Rate Authority as one of the most significant elements of his plan to remake the nation’s health care system.

Representative Jan Schakowsky, Democrat of Illinois, said that in a meeting with liberal Democrats last week, Mr. Obama “focused in particular on the new provision that would allow the Department of Health and Human Services to block exorbitant premium increases.”

As an example, Mr. Obama has pointed to a request by Anthem Blue Cross to increase premiums for individual policyholders in California by an average of 25 percent, with some rates going up as much as 39 percent.

Kathleen Sebelius, the secretary of health and human services, called Monday on five big insurers to provide detailed public justifications for their latest premium increases.

“If insurance companies are going to raise rates, the least they can do is tell us why,” said Ms. Sebelius, who has called their profits “wildly excessive.”