After an emotional debate, capping a Saturday night session that dragged into Sunday, the House voted 231-192 to add a one-year delay of Obamacare to the short-term funding bill that would keep the government open through mid-December.
Two Democrats -- Jim Matheson of Utah and Mike McIntyre of North Carolina -- voted with Republicans to add the provision. Two GOP representatives, Chris Gibson and Richard Hanna, both from New York, voted against the measure.
"Now that the House has again acted, it's up to the Senate to pass this bill without delay to stop a government shutdown," House Speaker John Boehner said after the vote. "Let's get this done."
Earlier, the House voted 248-174 to add a repeal of an unpopular medical device tax to the continuing resolution. In that vote, 17 Democrats joined with every Republican.
In the final vote of the nights, the House voted unanimously (423-0) to ensure that paychecks go to uniformed and civilian employees of the Defense Department in the event of a government shutdown.
With the evening's votes, it now seems fairly likely one will happen.
The signs were there all day Saturday that federal government was inching closer to its first shutdown in nearly two decades, with House Republicans taking a hard line in their push for a one-year delay of President Obama's health care law as a condition to keep the government running after the fiscal year ends on Monday.
The House was escalating an already-bitter confrontation with the Senate and the White House. The finger-pointing in the budget debate quickly moved to a fight over who should bear the blame for a government shutdown.
"The American people don't want a government shutdown, and they don't want Obamacare," Boehner and other Republican leaders said in a statement. "We will do our job and send this bill over and then it's up to the Senate to pass it and stop a government shutdown."
The Senate, controlled by Democrats, has repeatedly pledged to reject any budget plan that delays or defunds the Affordable Care Act.
The decision by House Republicans makes it increasingly more likely the government would shut down Tuesday -- at least for a short time -- unless lawmakers agree on a short-term emergency spending bill while trying to resolve their differences.
House Republicans gathered behind closed doors today in the basement of the Capitol for a rare Saturday strategy session. Booming applause and at least one lawmaker shouting, "Let's Roll," seemed to underscore the party's unified front.
"It has united us around a couple of very important principles," said Rep. Hal Rogers, R-Ky., chairman of the Appropriations Committee, adding that it was important for House members to take another stand against the health care law.
When asked whether he agreed that a government shutdown was unavoidable, he replied, "Not necessarily."
"They can make this work if they really put their mind to it and work hard," Rogers said.
But there was also an air of anxiety, particularly among some senior House Republicans, who worry about the repercussions of a government shutdown when the plan is almost certainly rejected by Senate Democrats.
The Senate is scheduled to be out of session until Monday at 2 p.m., and aides said Saturday it remained an open question whether senators would return to Washington sooner to deal with the House bill.
"Today's vote by House Republicans is pointless," Senate Majority Leader Harry Reid said in a statement. "As I have said repeatedly, the Senate will reject any Republican attempt to force changes to the Affordable Care Act through a mandatory government funding bill or the debt ceiling."
When asked what would happen if the Senate overruled the House action for a second time in less than a week, Rep. Darrell Issa, R-Calif., came alive with anger as he spoke to reporters.
He boomed, "How dare you presume a failure? How dare you? How dare you?!"
"No one's shutting down the government except the president," he said.
Rep. Nancy Pelosi, the Democratic leader, reacted sharply to the Republican proposal. She said there was still time to work together to avoid a shutdown, but said Republicans are to blame for pushing a bill that is dead-on-arrival in the Senate.
"Republicans have made their point, now we have to end it," Pelosi said. "They must abandon this dangerous path to create a Republican government shutdown."
A day after the Senate passed its funding bill with a bipartisan coalition, House Republicans settled on a three-part plan: delaying the health care law for a year and repealing a tax on medical devices that helps pay for the health care law. In a separate measure, the House will also put forward a bill that ensures members of the military still get paid if the government shuts down.
The latest wave of acrimony between Congress and the White House is even more critical because of the confluence of factors: the end of a fiscal year, the nation must raise its borrowing limit by Oct. 17, and enrollment begins in October for the Affordable Care Act.
Republicans said they believed they could persuade the Obama administration to delay the president's signature health care law, which is still highly controversial and has had a rocky start.
"We were elected in the House of Representatives to try to be financially responsible," said Rep. Mo Brooks, R-Ala. "We were also elected to stop socialized medicine because of the danger it poses to America and the danger it poses to our financial solvency."
The divisions inside the Republican Party have been on full display this week, particularly in the Senate, after several Republicans abandoned Sen. Ted Cruz, R-Texas, in his effort to hold up the budget bill over his push to defund Obamacare.
Not only did 25 Republicans join Democrats in opposing him, several spoke out against him in unusually blunt terms. In the House, Republicans are unified, said Rep. Michele Bachmann, R-Minn., an original founder of the Tea Party caucus.
"We're excited," she said. "We're united."