By Daniella Diaz, Miranda Green and Rene Marsh, CNN

(CNN) -- Environmental Protection Agency Administrator Scott Pruitt announced Monday his agency's plans to withdraw the Clean Power Plan, the sweeping Obama-era rule regulating greenhouse gas emissions.

While speaking in Kentucky at an event with Senate Majority Leader Mitch McConnell, Pruitt said he will sign the proposed rule repealing Obama's plan Tuesday.

"When you think about what that rule meant, it was about picking winners and losers. Regulatory power should not be used by any regulatory body to pick winners and losers," he said at the event. "The past administration was using every bit of power and authority to use the EPA to pick winners and losers and how we generate electricity in this country. That's wrong."

CNN obtained a copy of the leaked proposal to repeal the milestone Clean Power Plan, the outcome of President Donald Trump's executive orders calling for the review of the plan and questions the legality of the original rule.

"Under the interpretation proposed in this notice, the CPP exceeds the EPA's statutory authority and would be repealed," the proposal reads. "The EPA welcomes comment on the legal interpretation addressed in this proposed rulemaking."

The proposal also says the EPA has yet to determine whether it will create an additional rule on the regulation of greenhouse gases.

Bloomberg News first reported on the repeal proposal.

The Clean Power Plan requires states to meet specific carbon emission reduction standards based on their individual energy consumption. The plan also includes an incentive program for states to get a head start on meeting standards on early deployment of renewable energy and low-income energy efficiency.

Under President Barack Obama, the EPA estimated the Clean Power Plan could prevent 2,700 to 6,600 premature deaths and 140,000 to 150,000 asthma attacks in children.

When asked earlier this year on Fox News about the health consequences of doing away with the Clean Power Plan, Pruitt ducked the question and focused on how the plan would cost jobs. He argued the plan was bureaucratic overreach.

"As much as we want to see progress made with clean air and clean water, with an understanding that we can also grow jobs, we have to do so within the framework of what Congress has passed," Pruitt said.

Former EPA employees have reacted harshly to the planned repeal of the rule. Obama's EPA administrator, Gina McCarthy, called the proposal "just plain backwards."

"A proposal to repeal the Clean Power Plan without any time line or even a commitment to propose a rule to reduce carbon pollution, isn't a step forward, it's a wholesale retreat from EPA's legal, scientific and moral obligation to address the threats of climate change," McCarthy said in a statement Friday.

Environmental advocacy groups quickly blasted Pruitt's decision, with many vowing to fight the measure in court.

"Now the public has an opportunity to weigh in, as EPA is required to accept public comment on the proposed repeal and a discussion paper on a replacement," Rhea Suh, president of the Natural Resources Defense Council, said in a statement Monday. "In addition, NRDC expects to take EPA to court when the Clean Power Plan repeal is made final."

When reports of the EPA's planned move began to be reported over the weekend, Environmental Defense Fund President Fred Krupp said repealing the plan without replacing it with any protections from "climate-destabilizing pollution" would fail to protect Americans from harmful pollution designated under the Clean Air Act.

And Michael Brune, executive director of the Sierra Club, said Trump and Pruitt are launching "one of the most egregious attacks" on public health and climate safety.

"No matter who is in the White House, the EPA is legally required to limit dangerous carbon pollution, and the Clean Power Plan is an achievable, affordable way to do that," Brune said in a Monday news release. "It is a key element in continuing the progress moving toward clean energy and retiring coal."

Former New York City Mayor Mike Bloomberg, whose philanthropy said it would donate $15 million toward supporting operations of the United Nations Framework Convention on Climate Change after the Trump administration announced intentions to withdraw from the Paris climate accord, tweeted his criticism of the repeal proposal Monday.

"The EPA can repeal the Clean Power Plan but not the laws of economics," Bloomberg tweeted. "This won't revive coal or stop the US from reaching our Paris goal."