(President Donald Trump meeting with Senate Republicans about healthcare in the East Room of the White House on June 27.REUTERS/Kevin Lamarque)

Senate Majority Leader Mitch McConnell's backup plan for his healthcare overhaul has already come apart less then 24 hours after he introduced it.

Sen. Lisa Murkowski on Tuesday became the third GOP senator to publicly announce an intent to vote against a motion to proceed, a key procedural vote, for a bill that would only repeal the Affordable Care Act, the law better known as Obamacare.

"I said in January that we should not repeal without a replacement," Murkowski told reporters on Tuesday. "And just an indefinite hold on this just creates more chaos and confusion."

Murkowski joined Sens. Susan Collins of Maine and Shelley Moore Capito of West Virginia in defecting from the repeal-only plan.

"I do not think that it's constructive to repeal a law that is so interwoven within our healthcare system without having a replacement plan in place," Collins said in a statement. "We can't just hope that we will pass a replacement within the next two years. Repealing without a replacement would create great uncertainty for individuals who rely on the ACA and cause further turmoil in the insurance markets."

Capito echoed those concerns.

"My position on this issue is driven by its impact on West Virginians," Capito said. "With that in mind, I cannot vote to repeal Obamacare without a replacement plan that addresses my concerns and the needs of West Virginians."

Other members of the conference, including Sen. Rob Portman of Ohio, said they were worried about the repeal-only method but did not explicitly state their intention to vote against a motion to proceed.

While the repeal would not go into effect for two years, theoretically giving Congress time to come up with a replacement, many experts predicted the uncertainty would cause chaos in the insurance markets.

Additionally, the nonpartisan Congressional Budget Office projected that a repeal-only bill would cause 32 million more Americans to be without health insurance in 2026 compared with the current system.

In a press conference following the news, McConnell mostly focused on the inability to get to 50 votes on the original repeal and replace plan.

"Everybody's given it their best shot, and as of today, we simply do not have 50 senators who agree on what can replace the existing law," McConnell told reporters.

When asked about the three votes against the repeal-only bill, McConnell deferred and said only that he planned to have a vote on it in the coming weeks.