Voting on strict party lines, the Senate Health, Education, Labor and Pensions Committee approved a bill on Wednesday to revamp the nation’s health care system, as Democrats said that the legislation held the promise of more universal health coverage and more effective and affordable medical care while Republicans argued that the measure was unaffordable and would lead not to better care but to the denial of it.

The committee vote was 13 to 10.

The acting committee chairman, Senator Christopher J. Dodd, Democrat of Connecticut, had made clear from the start that his panel would bend little when it came to the top priorities of Senate Democrats and the Obama administration, including on a provision to create a government-run health insurance plan to compete with private insurers that Republicans insisted was a deal-breaker.

In the end however, Republicans held their ranks. In his closing statement, Senator Michael B. Enzi of Wyoming said that Republicans had been forced to offer more than 100 amendments to the bill because Democrats had largely shut them out of the drafting process. And he said that the $1 trillion, 10-year cost of the measure would simply drive the nation further into debt, while denying many Americans the choices for health care providers that they now enjoy.

Mr. Enzi, with a hint of sarcasm, noted that the bill’s title was the “Affordable Health Choices Act.”

“With its trillion-dollar price tag,” Mr. Enzi said, “this bill is anything but affordable.”

Committee Chairman Edward M. Kennedy, Democrat of Massachusetts, thanked Mr. Dodd and other committee members in a quickly issued statement that commended the bill’s passage and urged for bipartisanship going forward.

“It is a cause that can and should unite us all as Americans,” he said in a statement issued from Hyannis Port, Mass., where he is battling brain cancer. “As we move from our committee room to the Senate floor, we must continue the search for solutions that unite us, so that the great promise of quality affordable health care for all can be fulfilled.”

Both Republicans and Democrats acknowledged that the health committee bill was just part of what will eventually be a single Senate measure once the Finance Committee completes work on its version of the legislation.

The Finance Committee chairman, Senator Max Baucus, Democrat of Montana, has been making the one real effort to develop a bipartisan bill, and though negotiations with Republicans seem to have stumbled in recent days, committee members say they remain optimistic of a deal.

After a meeting of Finance Committee Democrats on Wednesday morning, the senators emerged to say that, despite pressure from the White House, they would not be bound by deadlines, including the president’s insistence that bills be completed before the summer break.

Senator Charles E. Schumer of New York, the No. 3 Democrat in the majority leadership, said the efforts to broker a bipartisan deal with Republicans remained on track and Democrats had no intention at this point of pushing health care legislation on their own.

At a news conference after the health committee vote, Mr. Enzi, who is also a member of the Finance Committee, said he remained “hopeful” of a deal in the Finance Committee but that he was worried about how the health and finance committee bills would be joined.

Senator Kent Conrad, Democrat of North Dakota, said that negotiators continued to discuss some of the most controversial issues including a compromise on the government-run insurance plan that would instead use nonprofit health cooperatives to provide the desire competition with for-profit insurers.

Mr. Conrad said negotiators had made some progress on the contentious question of how to pay for the bill, but had no choice but to continue a time-consuming “iterative” process, waiting for various proposals to be evaluated by the Congressional Budget Office for cost estimates.

In addition to widespread Republican resistance to the government insurance plan, Democrats are also contending with apprehension within their own ranks. Centrist lawmakers including Ben Nelson of Nebraska, Mark Pryor and Blanche Lincoln of Arkansas, Mary Landrieu of Lousiana and Joseph I. Lieberman, the Connecticut Independent, have all expressed reservations about the idea.

To avoid the hard-nosed budgetary tactic known as reconciliation–in which Democrats could pass a health measure with a simple majority vote–the Democrats would need 60 Senate votes to advance the health care bill. To get that, they must either ensure unanimity in their own party or win over Republicans to make up any gap. And so far, even the most centrist Republicans, Olympia J. Snowe and Susan Collins of Maine, have shown no inclination to break with their Republican colleagues on the health care measure.

The health committee bill, like the House version of the health care legislation unveiled on Tuesday, requires Americans to obtain health insurance and would provide subsidies to the poor to help them to do so. And it similarly requires most employers to provide health coverage to their employees or to pay a fee to the government instead.

It would establish stringent federal rules for health insurance, now regulated mainly by the states. Insurers could not deny coverage to people because of their medical history or health status, nor could they charge higher premiums because of a person’s claims experience or sex. Additionally, insurers could not establish lifetime or annual limits on the dollar value of benefits for any person. And they could not charge more than minimal co-payments for preventive services.

The bill, again like the one introduced by House Democrats, would establish a new government insurance plan, which would compete with private insurers. The secretary of health and human services would set premiums to cover costs of the new public plan, and she would pay for services at rates to be negotiated with doctors, hospitals and other health care providers.

People could compare insurance polices and buy coverage through new entities known as insurance exchanges, or gateways, in each state. The government would offer financial assistance, on a sliding scale, to people with incomes up to four times the poverty level ($88,200 for a family of four) to help them afford the premiums.

Robert Pear contributed reporting.