WASHINGTON - President Barack Obama made a last-minute personal appeal to Democrats to pass landmark health care legislation Saturday as the House voted to advance debate on a bill to expand coverage to millions of the uninsured.

Emerging from a closed-door meeting with the president, Speaker Nancy Pelosi predicted approval of the bill later in the day, adding, "We will pass health care reform."

"He came here to say, ’This is what we said we would do in the campaign. Let’s do it,’" Majority Leader Steny Hoyer said after the meeting.

The president later issued a public appeal from the White House Rose Garden.

"What’s in our grasp right now is a chance to prevent a future where every day, 14,000 Americans continue to lose their health insurance, and every year, 18,000 Americans die because they don’t have it," Obama said.

Not long after the president left the Capitol, the legislation cleared its first big hurdle on the House floor, as lawmakers voted 242-192 to approve a must-pass procedural measure setting the terms for the debate. Fifteen Democrats joined all 177 Republicans in voting to block the debate.

Obama made his trip to the Capitol complex as abortion rights lawmakers voiced anger at a last-minute concession granted to foes of the procedure, who were given a vote on their proposal for stronger restrictions on abortion coverage.

"There is a risk" that some in the Pro-Choice Caucus would vote against the legislation if the stricter curbs are adopted, said Rep. Diana DeGette, D-Colo.

The bill would cost $1.2 trillion over the next decade. It would provide health coverage to tens of millions of Americans who don’t have it now, require most employers to offer it to their workers and prohibit insurance companies from denying coverage based on a person’s medical history.

"The status quo is unaffordable and unsustainable. Health care reform benefits all of us," said Rep. Allyson Schwartz, D-Pa., as debate opened on the House floor.

House passage of the bill is crucial if Obama is to accomplish his top domestic priority and fulfill the biggest promise of his campaign last year. But the legislation still faces multiple hurdles, and a Senate vote on it might not occur until next year.

Republicans were united in their opposition to the bill.

"The American people need to understand this is about a government takeover of the whole health care system," said Rep. Paul Broun, R-Ga.

The most contentious issue is a new government-run insurance plan that would be offered alongside private coverage within new purchasing marketplaces, or "exchanges," where individuals and small businesses could shop for and compare options.

The abortion agreement was reached at midnight Friday after hours of intense negotiations brokered by Pelosi, D-Calif. Democratic Reps. Bart Stupak of Michigan, Brad Ellsworth of Indiana and other abortion opponents fought for and won an opportunity to insert tougher restrictions into the legislation during debate, despite fervent opposition from pro-choice liberals who are a driving force behind the overall bill.

"We wish to maintain current law, which says no public funding for abortion," Stupak said.