"There's a pretty straightforward solution to this," Obama said at the White House. That's for "everybody to act responsibly and do what's right for the American people."
The Democratic-led Senate was expected to reject a measure passed by the Republican-led House to tie government funding to a delay in the health plan. Then it will be up to the House to accept a spending bill that doesn't delay the health initiative—which it has refused to do—or find an alternative acceptable to the Senate.
If it fails to do either of those options, the government faces closures that would force 800,000 federal workers off the job without pay and rattle the shaky U.S. economic recovery.
The prospect of a shutdown contributed to a decline in stock markets around the world, and U.S. stocks tumbled sharply after Wall Street opened Monday.
Some critical services would continue, such as patrolling the borders, inspecting meat and controlling air traffic, and healthcare programs for the poor and elderly. The State Department would continue processing foreign applications for visas, and embassies and consulates overseas would continue to provide services to American citizens.
Since the last government shutdown in 1995-1996, temporary funding bills have been noncontroversial, with neither party willing to chance a shutdown to achieve legislative goals it couldn't otherwise win.
But with the 3-year-old healthcare law nearing implementation, hardcore tea party conservatives are determined to block it.
Even if Congress averts a shutdown, Republicans are sure to move the healthcare fight to another must-do measure looming in mid-October: a bill to increase the government's borrowing cap to avert a market-rattling, first-ever default on U.S. obligations.
Both a shutdown and a default would be politically risky ahead of next year's congressional elections, and the crisis has divided the Republican Party.
Some Republican leaders fear the public will blame their party for a shutdown if they insist on crippling healthcare reform. But individual House members may face a greater risk by embracing a compromise. Many represent heavily partisan congressional districts, and voters in primaries have ousted lawmakers, particularly Republicans, they see as too moderate.
There are few issues Republicans, especially those in the small-government tea party movement, feel as passionately about as Obama's health care plan. They see the plan, intended to provide coverage for the millions of Americans now uninsured, as wasteful and restricting freedom by requiring most Americans to have insurance.
A crucial part of the plan will begin Tuesday, whether or not the government partially closes: enrollment in new healthcare exchanges for millions of Americans. That's because most of the program is paid from monies not subject to congressional appropriations.
The shutdown battle started with a House vote to pass the short-term funding bill with a provision that would have defunded implementation of the health care overhaul. The Senate voted along party lines to strip that out and lobbed the measure back to the House.
The latest House measure, passed early Sunday by a near party-line vote of 231-192, sent back to the Senate two key changes: a one year delay of key provisions of the health insurance law and repeal of a new tax on medical devices that partially funds it, steps that still go too far for The White House and its Democratic allies.
The Democrats have accused Republicans of holding a routine spending bill hostage to get their way on healthcare. Republicans insist they have already made compromises; for instance, their latest measure would leave intact most parts of the healthcare law that have taken effect, including requiring insurance companies to cover people with pre-existing conditions.