Senator Charles E. Schumer, the New York Democrat and a member of the Finance committee, said on NBC’s “Meet the Press” that President Obama “believes strongly in a public option.”

He argued that a government plan was imperative because it would introduce competition in the industry. In 40 of the 50 states, he said, as few as two companies rule the private health insurance market. A government program, he said, “doesn’t have to make a profit or merchandise as much, so its costs are probably 20 percent lower.”

But on the same show, Senator Orrin G. Hatch, the Utah Republican and a member of the same finance panel, predicted that “tens of millions of people will go into the government plan” against their will. And, he added, the problem with government plans like Medicare is they are not sufficiently financed. Medicare, he said, will go bankrupt within 10 years.

“The costs of the government plan will be astronomical,” he said. “Keep in mind, in Medicare they pay doctors 20 percent less, they pay hospitals 30 percent less. Guess where those costs are transferred? They’re transferred to the people who have private health insurance, and the average private health insurance policy goes up about $1,800 a year just to pay for what the government fails to pay for in their current government plan.”

But on CBS’s “Face the Nation,” Howard B. Dean, former governor of Vermont and former chair of the Democratic National Committee, said a government program would be far cheaper than any private alternatives. Mr. Dean said that only 80 percent of the revenue of private insurance companies goes to medical care while the rest becomes profits for investors in the insurance company and for costs like administration. With Medicare, he said, 96 percent of revenue ends up being spent on actual health care.

Senator McCain said President Obama is as much to blame as Republicans for the paralysis on health care legislation because “the president has not come forward with a plan of his own.” He lamented the absence of Senator Kennedy, who is ailing with brain cancer, from the Congressional debate. Senator Kennedy, he said, has had “a unique way” of getting Senators “sitting down at the table and making the right concessions.”

While Mr. McCain rejected the term “death panels”  deployed by his running mate, Sarah Palin  but he said that the language in some bills would have created boards to decide what procedures would be allowed for the terminally sick and dying.