With five days until a possible U.S. government shutdown, lawmakers were mulling options Thursday for keeping agencies open while potentially postponing a battle over President Barack Obama's health care law.

The Senate expected to approve a stopgap funding bill soon that strips out a provision defunding the controversial health law, while House Republicans were to confer early Thursday over possible plans to shift the health care fight to mid-October, when lawmakers will need to raise the debt ceiling.

Congress is deeply fractured over how to spend within the government's means, and they have yet to come to terms over a budget that funds federal operations beyond next Monday, the final day of the current fiscal year.

After the Senate moved forward Wednesday on the temporary spending bill, the chamber's top Democrat Harry Reid stripped it of the health care provision, insisting that nothing that defunds so-called "Obamacare" will pass the Senate, as it did in the House.

Republican and Democratic leaders agreed to compress the procedural time before the next Senate vote, meaning the chamber could pass its legislation on Saturday, leaving the lower house barely 48 hours to pass the amended bill.

Any changes to the bill by House Speaker John Boehner would require the reworked version to go back to the Senate for approval, almost certainly leading to a government shutdown.

"I would hope we can expedite this," Reid said. "We have a lot to do and I hope we can get there as quickly as we can."

If no deal is reached, many government agencies would shut down beginning Tuesday, and hundreds of thousands of federal workers would be ordered to stay home with no pay.

Meanwhile, a congressional source said House Republicans were considering reworking their budget measure to include a one-year delay of Obamacare's so-called individual mandate, which requires nearly all Americans to have insurance by January 2014 or pay a fine.

"It is an option that some people like," a Republican aide told AFP.

Other Republicans, however, have spoken of the potential for passing a clean stopgap budget and shifting the Obamacare fight to the debt ceiling, where they feel they might have more leverage.

Boehner's leadership team was expected to propose that plan to the caucus Thursday, according to the Washington Post.

With the attention earlier this week on the Senate, conservative Senator Ted Cruz took to the floor Tuesday for an extraordinary, 21-hour speech railing against Obamacare as "the biggest job killer in this country."

Many Republicans expressed opposition to Cruz's delay strategy, warning it could leave insufficient time for the House to consider the Senate measure.

They said Republicans would be blamed for a shutdown debacle, and it would hurt the party's standing with voters.

White House spokesman Jay Carney weighed in, saying "it would be irresponsible to not fund the essential functions of the government out of ideological pique."

As lawmakers squabble over the way forward, the need to raise the US debt ceiling was rapidly approaching.

Treasury Secretary Jacob Lew warned that the government will reach its statutory debt cap by October 17, and that failure to raise it would lead to "catastrophic" default.

"If we have insufficient cash on hand, it would be impossible for the United States of America to meet all of its obligations for the first time in our history," Lew said in a letter to Boehner.

Lew urged Congress to "act immediately" to increase the borrowing limit, which has been locked at $16.7 trillion since May.

Some Republicans have suggested that the House pass a measure this week that raises the debt ceiling but delays elements of the health law.

House Democratic leader Nancy Pelosi is squarely opposed to that approach, and she crafted a letter to Obama signed by 185 members of her caucus saying they "will support a clean extension of the debt ceiling when the House takes up this issue."

And Carney reiterated Obama's position that raising the debt ceiling "is not a subject of negotiation."

During a bruising 2011 budget battle, the matter of raising the debt ceiling was wrapped into the spending fight, and Lew reminded lawmakers that the 2011 impasse "caused significant harm to the economy."

That fight was resolved just hours before Treasury could have defaulted, but nevertheless led to a historic downgrade of the US credit rating, the first time the United States has ever lost its AAA status with Standard & Poor's.

[Image via Agence France-Presse]