Updated

Michigan Rep. Bart Stupak said Thursday he's counted 11 Democratic lawmakers in addition to himself who are willing to kill President Obama's health care overhaul over abortion language.

Stupak sponsored a provision in the House of Representatives' health care bill, which passed last fall, that clearly prohibits the use of federal money to pay for abortions. That language did not make it into the Senate bill, the model Obama is using to craft the plan he is expected to send to Congress shortly.

"We're not gonna vote for this bill with that kind of language in there," Stupak said Thursday in an interview on ABC's "Good Morning America."

"I want to see health care, but we're not gonna bypass some principles and belief that we feel strongly about," he said, adding that he's "prepared to take responsibility" for bringing down the bill.

President Obama is hoping the legislation will pass in the House by March 18, White House Press Secretary Robert Gibbs said Thursday.

"The president leaves for Indonesia and Asutralia on March 18," Gibbs told reporters, and "I believe that based on conversations that I've had with people in the building that we are on schedule to get this through the House by then."

Obama has urged the Senate to use the "reconciliation" procedure to pass the bill, which would allow Democrats to avoid a 60-vote majority needed to strike down a filibuster but would demand that lawmakers vote only on matters that impact the budget. But before that happens, House Democrats can prevent the legislation from reaching the Senate.

House legislation passed by a narrow 220-215 margin in November. Since then several Democrats have defected or departed, and all 254 who remain are eyeing November midterm elections and a restive electorate demanding Congress focus on jobs.

Thirty-nine Democrats voted "no" on the House bill, and House Speaker Nancy Pelosi, D-Calif., will probably need some of them to switch their votes.

Abortion is one item that can not be tweaked in the reconciliation method. Senate Democrats have talked about a wholly separate bill for issues that can't be "fixed" in reconciliation.

Without referring to abortion, Health and Human Services Secretary Kathleen Sebelius told Fox News on Thursday that every aspect of health care has an effect on the budget.

"There is no question (health care issues) impact the budget. They impact family budgets, they impact government budgets."

But Sebelius also told ABC's "Good Morning America" that there will be no federal funding for abortion.

This bill does not change the status quo on abortion, she said.

House Minority Leader John Boehner, R-Ohio, told Fox News on Thursday that he doesn't anticipate that the bill will pass, saying, "It's pretty clear to me they're having a tough time getting the votes."

On abortion, Boehner said, "I've always believed that it was one of those issues that, literally, can't split the baby."

"The fact is the bill that they're talking about provides for public funding of abortion," he said.

Other rank-and-file Democrats say they remain wary of the legislation, not only because of its substance but because of the political peril a "yes" vote would cause back home.

Rep. Dan Boren of Oklahoma, a Blue Dog Democrat opposed to the bill, has expressed concerns that tax increases on small businesses and mandates on employers will lead to more job losses.

"They'll have to walk across my dead body if they want my vote on this issue," Boren told Fox News on Wednesday. "This is so galvanizing in my district. I think the votes are not there and I don't see where we get them."

On the other side of the party, liberal Democrats say they can't support the legislation because it does not have a so-called public option.

In a speech Wednesday at the White House, Obama called on lawmakers to end a year of legislative struggle and angry public debate and enact legislation ushering in near-universal health coverage for the first time in the country's history.

"At stake right now is not just our ability to solve this problem, but our ability to solve any problem," the president said. "And so I ask Congress to finish its work, and I look forward to signing this reform into law."

Appearing before a select audience, many of them wearing white medical coats, Obama firmly rejected calls from Republicans to draft new legislation from scratch.

"I don't see how another year of negotiations would help," he said. "I believe the United States Congress owes the American people a final vote."

Underscoring the pressure, many of the "no" voters made themselves scarce Wednesday while others said they had to wait to study Obama's plan before stating their position.

"I haven't seen the president's proposal so I'm going to look at it," said first-term Rep. Scott Murphy, D-N.Y

"It's fragile," Rep. Joe Courtney, D-Conn., said of the mood in the House. "It's getting close to the election."

Nonetheless, Pelosi vowed to answer the president's call.

"Our families and businesses deserve reform that will create millions of jobs, strengthen Medicare, reduce our deficit and no longer deny care or drop coverage to those who need it most," Pelosi said. "We must act now."

Republicans said Democrats would be sorry.

"Americans do not want a trillion-dollar government takeover of health care stuffed with tax hikes, Medicare cuts and giveaways to Washington special interests," Boehner said. "Not today, not tomorrow, not ever."

Obama has already made plans to try to sell the legislation directly to the public in states home to opposed or wavering lawmakers, with visits planned Monday to Philadelphia and Wednesday to St. Louis.

At its core, the legislation still is largely along the lines Obama has long sought. It would extend coverage to tens of millions of uninsured Americans while cracking down on insurance company practices such as denying policies on the basis of pre-existing medical conditions. An insurance exchange would be created in which private companies could sell policies to consumers.

Much of the cost of the legislation, nearly $1 trillion over a decade, would be financed by cuts in future Medicare payments and higher payroll taxes on individuals earning more than $200,000 and couples more than $250,000.

At an Obama-sponsored health care summit last Thursday, Republican Rep. Paul Ryan said that double-counting Medicare savings to pay for the new program is part of an elaborate illusion to make the plan appear more affordable than it is.

In his latest changes Obama added some Republican ideas raised at last week's bipartisan summit, including renewed efforts on changes in medical malpractice and rooting out waste and fraud from the system. But Republicans say those are issues that tinker around the edges and don't do anything to slow the increasing price of health care.

The Associated Press contributed to this report.