WASHINGTON (AFP) - A tumultuous US House votes late Saturday on a Republican plan that keeps government open but is unlikely to pass the Senate, leading lawmakers to bicker over who is responsible for a likely shutdown.
Barely two days before a shutdown deadline, Republican leaders set off a political firestorm when they announced that their stopgap federal spending bill also aims to delay implementation of President Barack Obama's health care law by one year.
The move prompted a sharp rebuke from the White House, which warned it was a step towards shuttering federal agencies once the fiscal year ends on Monday night, and vowed to veto any such bill.
House Speaker John Boehner convened a rare Saturday session as Congress struggles to break a funding impasse that, if unresolved, would require hundreds of thousands of federal workers to stay home.
In addition, more than a million US military personnel would remain on duty - but with no pay.
Under pressure from his party's far-right conservative wing, Mr Boehner doubled down on his caucus's bid to stop Mr Obama's signature domestic achievement, the health care law, vowing to send a bill back to the Senate but with little time for legislative action to avoid a shutdown.
"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," Mr Boehner said.
The House had earlier passed a temporary budget bill known as a continuing resolution that included a provision defunding so-called Obamacare altogether.
The Democratic-led Senate stripped that part out and sent a clean budget back to the House.
But instead of passing it, the House plans to amend the bill with a one-year delay of the health care law and repeal of an unpopular medical device tax.
While conservative lawmakers hailed the move, the White House slammed it.
"Any member of the Republican Party who votes for this bill is voting for a shutdown," spokesman Jay Carney said.
In a separate statement, the White House Office of Management and Budget warned that Mr Obama "would veto the bill" if it reached his desk.
A furious Democratic Senate Majority Leader Harry Reid, meanwhile, attacked the move as "pointless" brinkmanship that could end in economic crisis.
"To be absolutely clear, the Senate will reject both the one-year delay of the Affordable Care Act and the repeal of the medical device tax," Mr Reid said.
"The American people will not be extorted by Tea Party anarchists."
Driving the point home, a Senate Democratic aide told AFP it was "highly unlikely" the chamber would be in session before Monday.
Given the Senate's likely rejection of the House bill in the waning hours of the fiscal year, a Republican aide acknowledged that a temporary shutdown was the likeliest scenario.
House Democrats, largely powerless to prevent passage of Republican legislation in the lower chamber, expressed worry that the US government would suffer the same fate as a Washington deadlock in late 1995 that resulted in a 21-day work stop.
"I think we are on our way" to a shutdown, said Democrat John Lewis, a 27-year House veteran. "We're closer now than ever before."
The finger pointing coursed through hours of contentious, raucous debate on the House floor, with Republicans charging that Democrats would be on the hook for any government closure.
Democrat David Scott stood up to say what was occurring was nothing less than "a shutdown being ordered by the Republican Party."
"You have been hijacked by a small group of extreme folks who simply hate this president," Mr Scott said, breaking protocol as he addressed Republican members directly.
"The American people are never going to forget that it was you who shut down the government."
Mr Boehner and fellow House leaders had struggled to stake out a position palatable to their divided members.
A chorus of criticism - including from Mr Obama and centrist Republicans in the Senate - accused Tea Party-backed lawmakers of unwisely threatening a shutdown if they did not get their way.
"How dare you presume a failure?" Congressman Darrell Issa barked at a reporter who asked what would happen when the Senate rejects the House measure.
"We continue to anticipate that there's an opportunity for sensible compromise."
Congress now has just 48 hours to strike a deal that keeps government open, but the ping-ponging of legislation is making that unlikely.
As if anticipating a possible shutdown, Mr Boehner said the House would vote on a separate measure "that ensures our troops get paid, no matter what."