Published: Sep 28, 2013 9:52 AM EDT

WASHINGTON (AP) - Divided Republicans are convening the House of Representatives this weekend in hopes of preventing a federal government shutdown, but remain under pressure from the party's conservative wing to battle on and try to derail all or part of President Barack Obama's health care law.
    
The weekend session comes after the Senate on Friday sent back to the House legislation to keep the government's doors open until Nov. 15, but only after Democrats stripped from the bill a provision to defund the health care law, frequently referred to as Obamacare, that aims to extend insurance coverage to millions.
    
Congress faces a midnight deadline on Monday. Failure to pass a short-term funding bill by then would mean the first partial government shutdown in almost 20 years. A single, agreed-upon version must be approved by both houses of Congress and signed by Obama by Tuesday.
    
The Senate's 54-44 vote was strictly along party lines in favor of the bill, which would prevent a shutdown of nonessential government services.
    
That tally followed a 79-19 vote to cut off an effort by Republican Sen. Ted Cruz to speak all night and through morning in favor of using the spending bill to kill the health care law, which Republican insist is an intrusion into individual decision-making.
    
The vote exposed a rift among Republicans eager to prevent a government shutdown for fear voters will blame them and those who are willing to risk it.
    
Such paralyzing fiscal fights have dominated Washington in recent years, underscoring the deep divide between the Republicans and the Obama administration and its Democratic allies. The two sides have managed in the past to come up with last-minute compromises to avoid a government closure.
    
Cruz was whipping up House conservatives, urging them to reject efforts by Speaker John Boehner and other Republican leaders to offer scaled-back assaults on the law, like repealing a tax on medical devices.
    
"I am confident the House of Representatives will continue to stand its ground, continue to listen to the American people and ... stop this train wreck, this nightmare that is Obamacare," Cruz said.
    
Republican leaders had yet to announce a plan heading into an emergency meeting Saturday afternoon of House Republicans. A vote on the as-yet-unwritten measure seemed most likely on Sunday, leaving little time for the Senate to respond on Monday.
    
Democratic Majority Leader Harry Reid warned that the Senate will not accept any House measure that contains provisions opposed by Democrats.
    
"This is it. Time is gone," Reid said in a warning to Republicans. "They should think very carefully about their next steps. Any bill that continues to play political games will force a government shutdown."
    
Obama criticized conservative Republicans on Saturday in his weekly radio and Internet address.
    
"Republicans in the House have been more concerned with appeasing an extreme faction of their party than working to pass a budget that creates new jobs or strengthens the middle class," the president said.
    
Late on Friday, more than five dozen conservatives rallied behind an amendment by Republican Rep. Tom Graves to delay Obamacare through the end of next year. It's a nonstarter with the Senate.
    
If lawmakers blow the deadline, hundreds of thousands of nonessential federal workers would have to stay home on Tuesday, though critical services like patrolling the borders, inspecting meat and controlling air traffic would continue. Retirement benefits would be sent and health care programs for the elderly and poor would continue to pay doctors and hospitals.
    
"I'm more concerned about the impact of this law on the American people than I am about my re-election," said Republican Rep. Richard Hudson.
    
But party veterans warn that the political risk of a shutdown is simply too great.
    
(Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)