WASHINGTON (AP) Congress has missed the deadline for averting the first partial government shutdown in 17 years.
As the clock struck midnight in Washington on Monday, House Republicans were demanding that the Senate negotiate their demand for a one-year delay in making millions of people buy health insurance under President Barack Obama's 2010 health care law.
Minutes before midnight, the White House ordered a shutdown.
The Democratic Senate on Monday twice rejected GOP demands to delay key portions of what has become known as Obamacare as a condition for keeping the government open. An estimated 800,000 federal workers faced furloughs, though many were told to work a half day Tuesday.
Critical functions like air traffic control and military operations will continue. Social Security benefits will be paid.
National parks and most federal offices will close.
Earlier, House Republicans scaled back their demands to delay the nation's health care law Monday night as the price for essential federal funding, but President Barack Obama and Democrats rejected the proposals as quickly as they were made.
We're at the brink, said Sen. Barbara Mikulski, D-Md.
On a long day and night in the Capitol, the Senate torpedoed one GOP attempt to tie government financing to changes in Obamacare. House Republicans countered with a second despite unmistakable signs their unity was fraying - and Senate Democrats promptly rejected it, as well.
The stock market dropped on fears that political gridlock between the White House and a tea party-heavy Republican Party would prevail, though analysts suggested significant damage to the national economy was unlikely unless a shutdown lasted more than a few days.
Still, the shutdown will send hundreds of thousands of workers home and inconvenience millions of people who rely on federal services or are drawn to the nation's parks and other attractions. Some critical parts of the government - from the military to air traffic controllers - will remain open.
As lawmakers squabbled, President Barack Obama spoke bluntly about House Republicans. You don't get to extract a ransom for doing your job, for doing what you're supposed to be doing anyway, or just because there's a law there that you don't like, he said. Speaking of the health care law that undergoes a major expansion on Tuesday, he said emphatically, That funding is already in place. You can't shut it down.
House Speaker John Boehner responded a few hours later on the House floor. The American people don't want a shutdown and neither do I, he said. Yet, he added, the new health care law is having a devastating impact. ... Something has to be done.