Wisconsin Sen. Ron Johnson said Monday that he confirmed with colleagues that Senate Majority Leader Mitch McConnell told centrists not to worry about planned cuts to Medicaid because they likely would never take effect, a revelation he said put the bill's passage in jeopardy.

According to the Wisconsin Republican, McConnell told senators regarding concerns they had about federal reductions in Medicaid funding, "Don't worry about that, that's too far in the future."

Johnson told reporters that he had been strongly in favor of moving forward on debating the bill until he heard those comments.

"I find those comments very troubling, and I really think that puts in jeopardy the motion to proceed vote," he said. "Last week I was strongly urging colleagues to vote motion to proceed. I'm not doing that right now."

Asked about the comments, McConnell released a statement saying, "I prefer to speak for myself, and my view is that the Medicaid per capita cap with a responsible growth rate that is sustainable for taxpayers is the most important long-term reform in the bill. That is why it has been in each draft we have released."

The Senate bill's changes to Medicaid, which covers low-income people, as well as children, people who are disabled, and adults in nursing homes, have been particularly controversial among Republicans as they seek to reach an agreement on a bill that would partially repeal and replace Obamacare.

The bill would roll back Obamacare's expansion of Medicaid in states that allowed coverage to go to all low-income residents. Over the long term, it would allow states to choose between receiving a fixed amount of federal dollars from Medicaid as a per-capita cap or a block grant and would reconfigure the program's growth rate to match overall inflation rather than faster-increasing medical inflation, as it does now. The Congressional Budget Office estimates that those changes would result in cuts of $772 billion in federal spending on Medicaid and would shed 15 million people from the program.

Conservatives such as Johnson support making changes to Medicaid because they say it is growing at an unsustainable rate, and on Monday he reiterated that he believed continuing to extend coverage to "able-bodied, working-age, childless adults" would put the program at risk.

The changes to Medicaid in the bill, however, would not happen for several years, which means that future members of Congress could alter them. The expansion wouldn't fade until 2021, and the Medicaid growth rate wouldn't be altered until 2025. Still, the changes were encouraging to conservatives who have long sought to make changes to the program.

"I think it's a real breach of trust, those types of comments," Johnson said.

McConnell, R-Ky., announced Saturday that the vote would be delayed after Sen. John McCain, R-Ariz., said he would be spending a week in Arizona to recover from a procedure in which a blood clot was removed above his left eye. Two Republicans, Sens. Susan Collins of Maine and Rand Paul of Kentucky, already have come out against the bill, so the bill does not have enough support for passage without McCain. Republicans expected to vote on the bill this week, but they are waiting for a score from the Congressional Budget Office, which will project how much the legislation would cost and how many people could become uninsured if it were to become law.

Johnson said the extra time will allow for more negotiation on the legislation.

"I don't know what's going to happen to the bill," he said. "There is another week, from my standpoint, to try to improve the bill."