Congressional Republicans are proposing long and short-term alternatives to ObamaCare as the Supreme Court begins hearing oral arguments Wednesday in a case that has the potential to unravel the health care law.

The plaintiffs, four Virginia residents, argue that Americans who bought insurance through the federal ObamaCare exchange are not entitled to subsidies because the law says only those who bought policies in state exchanges are eligible.

At least 5.5 million Americans last year bought insurance on the federal exchange and received the subsidies.

Both sides in the case -- known as King v. Burwell -- generally agree that if the high court decides that millions of recipients are no longer eligible, they likely will no longer be able to afford insurance under ObamaCare and exit the system.

However, whether their departure would topple the entire health care law remains a matter of debate ahead of the expected high court ruling by June.

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Last week, Health and Human Services Secretary Sylvia Burwell said nullifying the subsidies would cause "massive damage to our health care system" and that the administration would have no way to fix it.

The administration and Democrats who enacted the 2010 law over unanimous GOP opposition also largely back studies showing the number of people who would loses the subsidies, in the form of tax credits, is as high as 7.5 million.

And a recent analysis by the health care firm Avalere found that those who would lose their subsidies as a result of the court ruling would have their premiums increase an average 225 percent.

Ed Haislmaier, a health care policy expert with the conservative-leaning Heritage Foundation, on Tuesday predicated some fallout, or “dislocation’ but not to such an extent.

“Is the sky going to fall?” he asked. “No, but it’s probably going to rain in some places.”

Several top Capitol Hill Republicans have in the past few days announced pending, short-term alternatives if the court invalidates the subsidies for residents of the 34 states that use the federal ObamaCare exchange, not their own.

Utah Sen. Orrin Hatch, chairman of the Senate Finance Committee, said last week that his plan will set the stage for a “more permanent fix” but did not provide specifics.

On Sunday, Hatch was joined by fellow GOP Sens. Lamar Alexander of Tennessee and John Barrasso of Wyoming in a Washington Post opinion piece saying they have a plan.

“We would provide financial assistance to help Americans keep the coverage they picked,” the senators wrote. "It would be unfair to allow families to lose their coverage, particularly in the middle of the year."

However, they also provided no specifics on how to pay for the lost subsidies -- estimated at $36.1 billion.

Most of the 34 states in question are GOP-run and represented in Congress by Republicans.

On Tuesday, an opinion offering by Reps. John Kline, R-Minn., Paul Ryan, R-Wis., and Fred Upton, R-Mich., appeared in The Wall Street Journal also presenting alternatives - but in more detail.

“No family should pay for this administration’s overreach,” the congressmen, chairmen, respectively, of the House committees on Education and Workforce, Ways and Means, and Energy and Commerce wrote.

“That is why House Republicans have formed a working group to propose a way out for the affected states if the court rules against the administration.”

The congressmen said their ObamaCare “off-ramp” will in part allow states to opt out of coverage requirements that are driving up costs, let Americans buy the policies they want and make insurers compete for customers, rather than force Americans to buy a government-approved health plan “under the threat of IRS fines.”

The Associated Press contributed to this story.