WASHINGTON — President Obama and House Democratic leaders worked furiously on Saturday to secure the votes needed to pass landmark health care legislation, with the outcome hinging on their effort to placate a small group of lawmakers who want the bill to include tighter limits on insurance coverage for abortions.
With the ground shifting by the hour, House Democratic leaders said they would drop a plan to approve the Senate health care bill without taking a direct vote on it — a maneuver that Republicans had denounced.
Instead, Democrats said they would first vote Sunday on a budget reconciliation bill including revisions to the Senate measure, and would then vote directly on the Senate bill itself. Many House Democrats had said they would oppose the Senate bill without changes.
Democrats said the outcome would be the same: the Senate bill would be sent to Mr. Obama, who would sign it into law, and the reconciliation bill would go to the Senate, which could take it up within days.
As Mr. Obama prepared to visit Capitol Hill for a meeting with House Democrats, Speaker Nancy Pelosi appeared to be within 10 votes of the 216 that she needs to approve the bill, with 21 Democrats still uncommitted. Republicans are all expected to oppose the bill, which is scheduled for a vote on Sunday.
On a day of high drama, with thousands of opponents of the health care legislation on the West Front of the Capitol chanting angry slogans, Ms. Pelosi expressed total confidence. “We will have the votes when we bring it to the floor,” she said, entering the House chamber on Saturday morning.
The speaker on Saturday rejected a proposal by Representative Bart Stupak, Democrat of Michigan and a leader of the abortion opponents, to revise the abortion provisions after the bill was adopted, a step typically used to make minor or technical changes and that requires approval of both the House and the Senate.
Instead, Democratic officials said they were pursuing the idea of promising an executive order that would prohibit the use of taxpayer money for abortions. They said that approach would not mollify Mr. Stupak but could win the support of others still undecided because of their views on abortion.
Ms. Pelosi, however, said she would not allow separate votes on abortion or other controversial issues. “Not on abortion, not on public option, not on single-payer, not on anything,” she said.
Behind the scenes, Ms. Pelosi was working aggressively to address the concerns of anti-abortion Democrats. She met with at least three of those lawmakers — Representatives Christopher Carney and Kathy Dahlkemper of Pennsylvania and Steve Driehaus of Ohio — none of whom had publicly decided.
The official action on Saturday was in the House Rules Committee, which labored to set the formal terms of the debate for Sunday’s showdown.
Before Democrats decided to take a direct vote on the Senate health care bill, Representative Joe L. Barton, Republican of Texas, described the plans to approve it without a direct vote as “a sleight-of-hand subterfuge” that would allow lawmakers to avoid accountability.
“This process corrupts and prostitutes the system” and could “unleash a cultural war” over the legislation, Mr. Barton said.
Democrats, however, tried to keep the focus on the substance of the health care legislation, which seeks to extend coverage to 32 million uninsured Americans.
“We are on the verge of taking a decisive step to providing access to all Americans, to affordable quality health care,” said Representative Henry A. Waxman, Democrat of California and chairman of the Energy and Commerce Committee. “If we do nothing, the system will go bankrupt, premiums will keep skyrocketing and benefits will keep getting slashed.”
The legislation would cost $940 billion over 10 years, according to the Congressional Budget Office, with the expense more than offset by revenues from new taxes, fees and reductions in spending on Medicare and other government programs. With those changes, the bill would reduce future deficits by $138 billion over that time period, the C.B.O. estimate found.
At a news conference on Saturday, 13 House Republican freshmen assailed the measure. “Let’s kill this bill,” said Representative Cynthia M. Lummis, Republican of Wyoming.
The late-hour maneuvering on abortion mirrored a similar process in November before the House adopted its version of the health care legislation.
In November, Mr. Stupak succeeded in winning approval of tight limits on insurance coverage of abortions in the House health care bill. But the current package now includes language from the Senate-passed bill, negotiated by two Democrats, Senators Bob Casey of Pennsylvania and Ben Nelson of Nebraska, who have built up solid credentials in their political careers as abortion opponents.
Once again, Mr. Stupak was opposed by a group of lawmakers who favor abortion rights, led by Representative Diana DeGette, Democrat of Colorado. And once again, at the center of the storm was Ms. Pelosi, the first woman to serve as House speaker, who is a champion of abortion rights.
The abortion issue has divided Roman Catholic groups in the United States, with the United States Conference of Catholic Bishops opposing the bill and other organizations, including the Catholic Health Association and a coalition of nuns from leading religious orders, favoring it.
Mr. Stupak and many of the lawmakers insisting on the tighter restrictions are Catholic, as is Ms. Pelosi, and all have cited their faith in justifying their position on the legislation.
In a sign of the emotion around the issue, Representative Dale E. Kildee, Democrat of Michigan, who is Catholic and opposes abortion, announced his support for the legislation in a statement noting that he had once studied for the priesthood. He said that he had consulted his priest and concluded that the abortion restrictions in the Senate bill were sufficient.
Democratic leaders said they hoped an executive order by Mr. Obama would clarify that the legislation was not intended to change existing federal law and policy that generally bar the use of taxpayer money for abortions.
“That is very good if the president does that,” said Representative Lynn Woolsey, Democrat of California, and co-chairwoman of the Congressional Progressive Caucus. “He will clear it up. The Senate bill does not allow federal funds to be used for abortion.”
Ms. DeGette said she welcomed the decision by the speaker not to negotiate with Mr. Stupak on the abortion provisions. She predicted passage of the bill and said abortion rights advocates would not object to an executive order specifying that federal dollars distributed under the health bill could not pay for abortions.
“We want this bill to be about health care, not abortion, and that is why we made our compromise,” she said.
But Representative Anh Cao of Louisiana, the only Republican who voted for the bill in November, said he could not support the current measure because of its “expansion of abortion, an absolute moral evil.”
Democratic lawmakers and top aides had worked into the predawn hours Saturday trying to address flare-ups over elements of the bill.
They said that they had worked out an agreement to resolve one of the last remaining issues: a dispute over geographic disparities in Medicare payments.
The agreement could lead to higher payments to doctors and hospitals in states like Iowa, Minnesota, Oregon, Washington and Wisconsin, where Medicare rates are relatively low but studies suggest that the quality of care is high.
Kathleen Sebelius, the secretary of health and human services, sent a letter to Congress saying she would commission studies by the National Academy of Sciences to investigate the issue and recommend solutions.
“The current geographic variation in Medicare reimbursement rates is inequitable,” Ms. Sebelius said. She promised to support payment adjustments that take account of such disparities and reward “high-value care.”
Carl Hulse contributed reporting.