President Obama is ramping up pressure on Republicans to avoid a post-midnight government shutdown.

WASHINGTON -- Republicans in the House approved another effort to delay President Obama's healthcare law, despite objections from some within the GOP that the party should stop the brinkmanship that has threatened to shut down the government at midnight.

The House voted 228-201 late Monday to delay for one year a major element of the law -- the requirement that by 2014 all Americans must carry health insurance or face a fine. The measure also included a provision that would hit lawmakers’ pocketbooks by ending the government’s long-standing payment of a portion of the healthcare premiums for members of Congress, their staffs and some administration officials.

With just hours to prevent a shutdown, the House measure heads to the Senate. Democrats, who have the majority in that chamber, already have vowed to reject the Republicans’ continued efforts to tie funds for government agencies to the fate of the Affordable Care Act -- efforts they have labeled  “extortion.”

“We are not going to mess around with Obamacare, no matter what they do,” said Senate Majority Leader Harry Reid (D-Nev). “They have got to get a life.”

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While Democrats have remained unified behind Reid, the high-stakes battle over a potential government shutdown has split Republicans. Their divisions were reflected in the runup to the vote. Tea party conservatives were unhappy because the measure would not fully end Obama's healthcare law; more moderate conservatives have tired of the stalemate and want to avert a shutdown.

To ward off potential rebellions from both right and left, Speaker John A. Boehner (R-Ohio) worked the House floor before a key procedural vote. The message, according to Rep. Peter T. King (R-N.Y.), who was among those trying to end the stalemate, was: “Trust me.”

Both rebellions fizzled.

In public, GOP leaders argued that after the Obama administration delayed a requirement that large businesses provide insurance, it should also delay the requirement that individuals purchase insurance.

“What our members want is fairness for the American people,” said Boehner. “We believe that everyone should be treated fairly.”

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White House officials say the two provisions have little to do with each other. More than 90% of large businesses already provide insurance, so the delay of the business requirement has limited practical impact. By contrast, the mandate that individuals purchase insurance is a key element of making the new law function.

Earlier Monday, Senate Democrats defeated an earlier GOP measure to delay the Affordable Care Act for one year and to repeal a new tax on makers of medical devices.

The Senate also unanimously agreed to a House-passed bill to ensure military troops are paid in the event of a government shutdown.

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lisa.mascaro@latimes.com

Twitter: @LisaMascaroinDC

michael.memoli@latimes.com

Twitter: @MikeMemoli