(Bloomberg) — At least three Republican senators said they would vote to block the Better Care Reconciliation Act bill, the current version of their party’s health care bill, from advancing, endangering Majority Leader Mitch McConnell’s plan to change the Affordable Care Act.

Republican Susan Collins of Maine late Monday said she would vote against a key procedural step, joining Rand Paul of Kentucky and Dean Heller of Nevada.

A new estimate from the Congressional Budget Office, which found the BCRA bill would leave an additional 22 million Americans without health insurance in a decade, has moved McConnell further away from the 50 votes he needs to pass the measure.

(Related: Senate Bill Could Add 22 Million to 2026 Uninsured Total: CBO)

“It’s a terrible bill,” Paul said. Collins, a moderate, said the CBO analysis showed the bill “doesn’t fix” the Affordable Care Act’s problems.

Republican leaders insisted they still hope to hold a final vote this week, and McConnell did get one piece of good news in the CBO estimate: an extra $200 billion in deficit savings compared to the House-passed bill. Some or all of that funding could be used to boost programs or subsidies to help win over some holdouts.

At least six Republican senators have said they’re not ready to support the current version of the health care bill, and McConnell can only afford to lose two and still pass the bill.

Sen. Ron Johnson of Wisconsin warned GOP leaders that holding a vote this week “would be a mistake. If Leader McConnell says failure is not an option, don’t set yourself up for failure.” He added that he didn’t think he would get enough information on the bill to be able to support advancing the bill this week.

“The current draft doesn’t have the votes to pass,“ Ted Cruz of Texas said, “but I believe we can get to yes.”

The Trump administration quickly blasted the CBO report, saying the agency has a “history of inaccuracy.”

But senators were taking the CBO estimate more seriously.

“If you’re looking at this as a political vote, the CBO report didn’t help you,” said Lindsey Graham of South Carolina, who said he won’t block the measure. “So I think it’s going to be harder to get to 50, not easier.”

Cruz blasted in particular the near-term cost increases that the CBO estimated. “At this point, we need to do significantly more to lower premiums,” he said.

Senate Minority Leader Chuck Schumer said the CBO report makes it clear “this bill is every bit as mean as the House bill.” He added, “I don’t count Senator McConnell out, but this is such a bad bill that even his legislative wizardry is having a rough time here.”

Dollar (Photo: Thinkstock)

(Photo: Thinkstock)

The CBO estimated the Senate health bill would raise costs for many people currently enrolled in private insurance and slash Medicaid by billions of dollars. It would reduce the deficit by $321 billion over a decade, according to the nonpartisan agency, significantly higher than the $119 billion in estimated savings from the version passed by the House in May.

Complicating the efforts of GOP leaders to win over holdouts is the CBO’s estimates that many Americans will face out-of-pocket costs and insurance premiums far higher than they are now.

The biggest increase in the uninsured would come from the bill’s rollback of Medicaid, the state-federal program that covers the poor. The GOP bill cuts spending on Medicaid by $772 billion over a decade, which would result in 15 million fewer people enrolled in the program in 2026 than under current law. Another 7 million wouldn’t have coverage in the individual insurance market.

The CBO estimated that the law would lower premiums in the long term, but raise out-of-pocket costs. Premiums would rise over the next several years and then fall, relative to current law. In 2026, average premiums would be about 20% lower than they would be under Obamacare. That’s in part because coverage would be skimpier, and people would face higher deductibles and other cost-sharing.

For example, a 64-year-old making $56,800 in 2026 would have a $6,800 annual premium after an $8,500 subsidy for a silver-level plan covering 70% of their expected health costs under existing law. That person would face a $20,500 premium for the same coverage under the Senate bill and get no subsidy.

The CBO estimated that the individual health insurance markets would be stable in most parts of the country under both the Senate GOP plan and under the Affordable Care Act. Under the Republican plan, though, insurers might withdraw from some rural parts of the country, because they’d have too few customers to operate profitably.

“The reductions in subsidies would lead fewer people to decide to purchase insurance — and markets with few purchasers are less profitable for insurers,” CBO said.

The political prospects for the overall bill remain unclear. Republican leaders are hoping to hold an important procedural vote on Tuesday or Wednesday to set up a vote on final passage at the end of the week.

While Heller and Collins have cited the cuts to Medicaid for their opposition, a bloc of four conservatives — Paul, Cruz, Johnson and Mike Lee of Utah — oppose the proposal for different reasons: They said the bill doesn’t go far enough in undoing the Affordable Care Act.

— Read 4 ACA Change Paths That Just Got More Popular on ThinkAdvisor.

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