Washington CNN  — 

If the Supreme Court decides against the Obama administration over subsidies that help cover health insurance costs at the heart of Obamacare, House Republicans are hatching a plan that would almost immediately reintroduce those same subsidies.

That means the same House GOP conference that has voted more than 50 times to repeal all or parts of Obamacare would be ready to offer a short-term transition period to keep those stripped of a subsidy afloat as they search for health insurance.

The move is likely an attempt to blunt any political fallout that could come if millions of people lose their ability to pay for health insurance, something Democrats would be sure to pin on Republicans.

But even if the GOP-led House and Senate pass this legislation, President Barack Obama has already pledged to veto any bill that rolls back all or significant parts of his signature health care law, as the Republican plan would eventually do.

The Supreme Court could rule in the case – Burwell vs. King – as soon as Thursday.

“We’ll be ready when the court rules,” Rep. Paul Ryan, the chair of the Ways and Means Committee, said Wednesday afternoon.

If the high court doesn’t uphold the current subsidies through the end of the year, the Republican plan would extend them through the end of 2015.

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Starting in 2016, states will get the chance to opt out of Obamacare and all of the mandates in the law and be eligible for block grants to cover those who lost their subsidies, according to the proposal. That amount will be equivalent to the subsidies the state was receiving under Obamacare.

“It’s a good start,” Louisiana GOP Rep. Charles Boustany said, noting the approach is designed to first take care of those who would be facing a loss of coverage and a mechanism for states to address the issue.

The entire Republican plan will be sunset in 2017 so that whoever the new president is will be forced to completely replace Obamacare.

Republican leaders in the House briefed members on the plan and also said they planned to use the reconciliation process to extend the subsidies, meaning the GOP would only need 51 votes in the Senate to win approval in that chamber, rather than the 60 needed for a filibuster-proof majority.

Four House GOP committee chairmen outlined said the plan, which would take effect on January 1, and would allow for a “smooth transition” into the first year of the new president’s tenure.

The new program, the committee chairmen said, would offer states block grants to cover those who have lost a subsidy. If the state declines that funding, Republican leaders said the federal government would sustain the subsidies for individuals for about two years.

Multiple Republican members and aides caution that the plan is not final, and Wednesday’s meeting was chance for leaders to outline the response and get input from rank-and-file members.

Some conservatives have been critical of any effort to continue any federal health care subsidies, arguing congressional Republicans should be working to dismantle all aspects of Obamacare.

But Florida Republican Dennis Ross defended the approach.

“I think that you just can’t leave these people – who are not victims of their own accord – without the ability to pay for their healthcare,” he told reporters.