WASHINGTON — A top White House official and several Republican senators said on Sunday that Congress should consider a stand-alone bill to repeal Obamacare if the Senate cannot agree on an alternative to replace the 2010 health care law.

“If the replacement part is too difficult for Republicans to come together, then let’s go back and take care of the first step and repeal,” Marc Short, the White House’s legislative affairs director, said on Fox News Sunday.

Short’s comments could undermine ongoing efforts by Senate Majority Leader Mitch McConnell, R-Ky., to pull together an agreement on health care during Congress’ Fourth of July recess. Senators left Washington last week after failing to meet their own self-imposed deadline to pass a bill that repeals and replaces the Affordable Care Act.

McConnell has vowed to keep working over the break to negotiate a deal, but his task is more difficult with lawmakers dispersed to their home states, where they’re under pressure from some constituents and activists who are vehemently opposed to the GOP’s draft bill. That draft would scale-back the Affordable Care Act’s Medicaid expansion and cut future spending on that safety-net program for the poor, disabled and elderly.

The draft stalled last week amid opposition from within the Senate GOP conference. Moderate Republicans in the Senate have balked at those proposed cuts, while conservatives say the draft measure does not go far enough to repeal the ACA’s regulations, such banning insurers from imposing lifetime caps on benefits or requiring coverage of substance abuse and pregnancy.

McConnell is “working the phones” and trying to put a deal together that balances those conflicting concerns, Scott Jennings, a Republican consultant and one-time McConnell adviser, said Sunday on CNN’s State of the Union. But Jennings acknowledged the delay would make McConnell’s task more difficult, giving opponents time to rally and ratchet up public pressure.

The idea of doing a stand-alone bill to repeal the ACA gained steam on Friday, when Sen. Ben Sasse, R-Neb., made the suggestion in a Fox News appearance. Within minutes of Sasse’s comments, President Trump tweeted an endorsement of that approach.

"If Republican Senators are unable to pass what they are working on now, they should immediately REPEAL, and then REPLACE at a later date!" the president tweeted on Friday.

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Sasse reiterated his support for such an approach in an appearance on CNN Sunday. But like Short, Sasse said he would prefer to have a combined bill that repeals and replaces Obamacare at the same time.

“If Leader McConnell can get us across the finish line ... that’s great,” Sasse said. “If we can’t though, there’s no reason to walk away. We should do repeal with a delay” and then craft an alternative health care plan on a separate track.

Sasse said the GOP should cancel its scheduled August recess and spend “18 hours a day, six days a week” holding hearings on a possible replacement bill.

Both Sasse and Short noted that 49 current Republican senators voted for repeal of Obamacare in 2015 and a 50th, now Sen. Todd Young of Indiana, was a House member at the time and also voted for repeal.

“You have 50 members on record having voted for that recently, so that’s an option,” Short said. “At that point, if you’ve repealed it, you can come back with a replacement effort that could be more bipartisan.”

Sen. Mike Lee, a conservative from Utah, said on CBS Face the Nation, said the idea of proceeding on two separate tracks is "very much worth considering" and could revive a now-stalled process.

"Sometimes when you lump too many things into one piece of legislation, you doom its likelihood of success and I fear that that might be where we are today," Lee said.

But even that idea could divide the Senate Republican conference. Lawmakers voted "yes" on repealing Obamacare in 2015, when they knew it would be vetoed by President Obama. Now that Trump is in the Oval Office and would sign such a measure, they might be more reticent because of the potential political fallout and economic uncertainty.

“You just can't get rid of this, because you can't leave people without what they need,” said Ohio's GOP Gov. John Kasich on ABC's This Week.

Democrats also blasted that approach, pointing to an estimate from the nonpartisan Congressional Budget Office that 32 million Americans would become uninsured over the next decade under a straight repeal bill.

“That idea is an absurd idea,” said Sen. Bernie Sanders, a Vermont independent and 2016 Democratic presidential contender. “You will throw 32 million Americans off health insurance, 10 percent of the population.”

Sanders said that would inevitably lead to deaths, and he said Republicans and Democrats should try to fix Obamacare instead of replacing it.

Contributing: Paul Singer.