Marylanders on both sides of the abortion divide are steeling themselves for a historic clash over the procedure, after lawmakers voted to prohibit federal subsidies for insurance that covers it.

Under the restriction, which was added late Saturday to make the House passage of the health care overhaul possible, elective abortions would not be covered by private insurance policies subsidized by the government or by the public option.

Local battle lines were taking shape as the issue threatened to recast the health care debate nationally. Since Saturday’s vote, dozens of House members have pledged to derail the entire overhaul if the abortion provision survives. And in the Senate, at least one Democrat emerged as a possible candidate to propose similar language.

If the restrictions become law, abortion rights supporters say, they would effectively deny access to the procedure for the low- and moderate-income Americans that the health care bill is intended to insure. But abortion opponents said it’s too early to celebrate.

“That addresses one major concern we had,” said Jeff Meister, chief lobbyist in Annapolis for Maryland Right to Life Inc. But he added: “Who knows what will come out of the Senate after they’re finished? There’s still a lot of work to be done.”

Rep. Donna Edwards, meanwhile, expressed confidence that what she called “this ridiculous, onerous, overextended” restriction would be stripped from the legislation before it returns for a final vote.

“I’m not just hopeful for it, I’m going to fight for it,” said the Prince George’s County Democrat, who joined colleagues Monday in letters to President Barack Obama and House Democratic leaders urging a reversal.

The measure, designed to attract moderate and conservative Democrats to support the bill, was the result of a furious lobbying effort Saturday by the U.S. Conference of Catholic Bishops. The Catholic church has long advocated for universal health insurance coverage, but opposes abortion.

“When it comes to abortion and research on human life, we can’t compromise on those things,” Archbishop Edwin F. O’Brien, spiritual leader of the area’s half million Catholics, said Monday. “Once we get the foundation established that human life has to be respected, then let the debate go on as to what the health bill will contain.”

In crafting the legislation, Democratic leaders had said they would honor a decades-long ban against using federal funds for abortion. But the way that they planned to accomplish this – requiring insurers to keep federal subsidies and patient contributions separate, and allow only the latter to be used to cover the procedure – left abortion opponents dubious.

With the new limits approved as an amendment, the House bill passed late Saturday 220-215. But in a stark turnabout, at least 40 House members furious about 11th-hour change have since threatened to torpedo the bill if the abortion language remains.

In the Senate on Monday, Ben Nelson, a Nebraska Democrat, said he would consider adding similar language to that body’s health care legislation. Because Democrats will likely need the vote of every member of their caucus to pass the bill, Nelson would have significant leverage in demanding tough abortion language.

Sen. Benjamin L. Cardin said such a move would complicate reform efforts.

“I thought the goal should have been for us to be neutral on the abortion issue,” said the Maryland Democrat, who received 100 percent ratings from NARAL Pro-Choice America and Planned Parenthood for 2008. “Health care reform is important in and of itself and to add to the controversy to take sides on the abortion issue to me, was something that should have been avoided.”

Cardin said he would oppose such a restriction, but said it was too early to say whether it would affect his vote on an overall health care package.

“It’s part of a weighing process of what’s in the bill and what’s not. … But as far as the final vote, that will very much rest on what’s in the bill and a strong desire to keep the process moving forward,” he said.

In the House, all of Maryland’s Democrats voted against adding the restriction. But once it was included, all but Rep. Frank Kratovil, a freshman facing a difficult re-election next year on the conservative-leaning Eastern Shore, voted for the overall bill.

“It was extremely difficult,” Edwards said. “It’s been well settled in federal law that federal funds can’t be used for abortion services. I think it is ridiculous to place restrictions on what a woman can do with her private funds.”

John Nugent, president of Maryland Planned Parenthood, sat glued to C-SPAN Saturday night, watching with building dismay as the House voted for the restriction.

“For me it violates the spirit and the ethical principle under which we began health care reform,” he said. “This restricts a whole segment of the population – it’s essentially throwing women of reproductive age under the train.”

According to NARAL, more than 85 percent of private plans cover abortion services. Nugent estimated that about a third of the women who get abortions in the Baltimore area pay for them with insurance.

“We stopped the abortion mandate in the House Bill, Praise God for this victory,” Glen Burnie abortion opponent Michael Martelli declared on Twitter. “But remember that the fight is far from over!”

He was right: By then, Maryland’s chapter of the National Organization for Women had posted an action alert on its Web site, urging supporters to get to Washington for a noon rally around the Capitol.

Nugent’s staff, meanwhile, had calls in to Maryland’s congressional delegation. Jennifer Blasdell, executive director of NARAL Pro-Choice Maryland, said the organization was focused on “defeating any attempt to add the amendment to the Senate bill.”

Abortion opponents readied for the fight.

“We know that the White House and pro-abortion congressional Democratic leaders will keep trying to enact government funding of abortion, and will keep trying to conceal their true intentions,” National Right To Life Committee lobbyist Douglas Johnson said. “There is a long battle ahead.”