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The Republican-led House voted to defund President Obama's health care overhaul on Friday during a sustained burst of floor activity, but with the White House and Senate Democrats vowing to block much of that activity, the government remains on a path to a shutdown if lawmakers can't reach a spending bill compromise in the coming weeks.

The House passed the health care measure, 239-187, as an amendment to a bill that would keep the government lights on through the end of the fiscal year but also impose deep cuts on domestic programs. The bill could come up for a final vote Saturday morning.

But if a stopgap bill isn't also passed by the Senate and signed by Obama, the government could shut down after March 4, when the current stopgap bill expires. The Republican measures have prompted a veto threat from Obama and face stiff opposition from the Democratic majority in the Senate.

Among the actions the House took Friday was to reject a controversial plan to end the Pentagon's sponsorship of a NASCAR team. Another measure, banning federal aid to Planned Parenthood, was passed.

The proposals were among more than 120 amendments remaining for the House to vote on as Republican leaders wind down a week of frenzied action on the $1.2 trillion spending bill.

The overall bill is the first step in an increasingly bitter struggle between Democrats and Republicans over how much to cut federal agencies' funding over the second half of the budget year that ends Sept. 30.

The focus of Friday's session was the health care overhaul, which dominated Congress' work in 2009 and was enacted last year.

Rep. Denny Rehberg's amendment would starve the overhaul of any federal funds for the rest of fiscal 2011, which ends Sept. 30. The GOP has virtually no chance of killing the law because of support for the program from Obama and the Democratic-run Senate, but House Republicans have been trying relentlessly to chip away at it.

"Today's vote is the latest victory for the American public and our country in preventing the disastrous Obamacare law from forever damaging our health care system and hampering job creation," Rehberg said in a written statement. "Our efforts -- and my amendment -- will save billions of wasted funding while opening the door for true health care reform that reduces costs and improve access."

House Democrats warned that defunding the bill would lead to repeal and an increase in the deficit and chided Republicans for attempting to gut the legislation through an amendment without hearings on the issue.

“It may pass on this floor, which is driving itself into irrelevancy with this amendment process,” said House Minority Leader Nancy Pelosi. But Pelosi insisted that Democrats would continue to fight efforts to dismantle the law.

Another amendment that made headlines was one introduced Wednesday by Rep. Betty McCollum that would have prevented the U.S. Army from spending $7 million on NASCAR and $5 million on drag racing in 2011 as well as millions more by the Air Force and Navy in sponsorship deals intended to generate recruitment interest. Her proposal sought to give Republicans another target for slashing wasteful spending.

McCollum, who appeared with Muppet characters at a news conference Wednesday to push for continued funding of public broadcasting, argued that too much money is being spent by the government on racing. She noted that the tax deal reached between Republicans and Obama at the end of 2010 grave breaks to track and facilities owners to fund capital projects at a cost of $40 million.

But NASCAR backers say McCollum ignores the value of the dollar spent at NASCAR. According to Col. Derek W. Crotts, who manages the Army's NASCAR marketing and advertising program, nearly one-third -- 46,000 -- of the 150,000 leads Army recruiters get each year come from motorsports events.

The amendment failed in a 281-148 vote.

Indiana Rep. Mike Pence's proposal targeting Planned Parenthood also captured national attention. His proposal would eliminate the more than $75 million a year the group receives from the federal government to provide family planning and sex education, mostly to poor women.

Even though the Hyde Amendment bans the use of taxpayer money for abortions, the debate on the Planned Parenthood amendment devolved into a testy, at times emotional exchange about abortion Thursday night, chewing up nearly three hours on the House floor.

That amendment passed 240-185.

"This afternoon's vote is a victory for taxpayers and a victory for life," Pence said in a statement. "By banning federal funding to Planned Parenthood, Congress has taken a stand for millions of Americans who believe their tax dollars should not be used to subsidize the largest abortion provider in America."

But Cecile Richards, president of Planned Parenthood, denounced the proposal as an "extreme and dangerous piece of legislation."

"The outcome of this vote is not a surprise, but it is radically out of step with mainstream American values and it is out of line with the issues voters want Congress to focus on," she said.

"To be clear, the amendment to prohibit Planned Parenthood from receiving federal funding does nothing to reduce the deficit and it does nothing to improve the economy," she added. "In fact, health professionals will actually lose their jobs as a result, and, most egregiously, it takes health care away from American women who cannot afford to pay for it on their own."

Another prominent amendment awaiting a vote would restore all funding to the Corporation for Public Broadcasting since the underlying bill eliminates the $460 million designated for public broadcasters.

House Democrats weren't the only ones who endured setbacks in the session. Republicans rejected requests from conservative members to cut even deeper in the spending bill.

By a 281-147 vote, the House refused to cut $22 billion more in domestic programs. The overall bill would cut $60 billion from federal programs in the remaining seven months of the government's current budget year.

The defeated proposal would have trimmed 5.5 percent more from domestic programs and 11 percent more from Congress' own budget. Defense and other security programs would have been exempted.

Democrats voted no overwhelmingly -- and Republicans who also voted that way said the plan went too far.

Fox News' Chad Pergram and The Associated Press contributed to this report.