Updated

Senate Minority Leader Mitch McConnell and 39 fellow Republicans are attempting to use a rarely used legislative tactic to block planned Environmental Protection Agency greenhouse gas standards that would limit the amount of carbon new power plants can emit.

The Kentucky senator filed a formal resolution of disapproval under the Congressional Review Act, a rarely used provision that allows Congress to block executive branch regulations that Congress considers onerous. The EPA rules were published in the Federal Register last week.

"Kentucky is facing a real crisis here," McConnell said Thursday in introducing the disapproval motion. Regulations imposed by the Obama administration have already cost hundreds of coal jobs in Kentucky, McConnell said, adding that the EPA rule "would effectively ban coal-fired power plants from being built in the future."

"The Obama administration appears to be sending signals that its latest regulation is just the beginning in a new, expanded front in its war on coal," said McConnell.

The agency's rules would impose tough new limits on the amount of carbon dioxide new plants are allowed to emit, essentially requiring any new coal plants to install expensive carbon-capture technology. Critics argue the technology is too expensive, not commercially available and poses safety risks.

The Sierra Club denounced the Republican effort as a "political maneuver."

"McConnell is attacking [the rules] before the Environmental Protection Agency has even determined what they will be. McConnell’s political maneuver is like asking for instant replay before the football is even snapped," Melinda Pierce, Sierra Club Deputy Legislative Director, said in a statement to The Wall Street Journal.

It was not clear Thursday when or if McConnell's motion would get an up-or-down vote on the Senate floor. The law has been used successfully only once since it was approved in 1996, according to congressional staffers.

Republicans on the Senate Environment and Public Works Committee accused the EPA of delaying the formal publication of the carbon pollution rules for political reasons, since they likely will not be finalized until after the 2014 elections. Publication in the Federal Register starts a one-year clock for the rule to be completed.

Sen James Inhofe, R-Okla., said the EPA's actions show a double standard by the Obama administration on climate change.

"On the one hand, the president says we don't have time to delay action on global warming," Inhofe said. "But on the other hand, his actions show it is OK to wait to finalize rules that will harm the economy until after the elections so they won't have an impact on vulnerable Senate Democrats who face voters this fall" in coal-producing states.

EPA Administrator Gina McCarthy said the agency submitted the rules for publication last fall and "tried very hard" to get them published in the Federal Register.

"As soon as that proposal was released, we had submitted it to the Federal Register office. The delay was solely the backup in the Federal Register office," McCarthy told the committee at a hearing this week.

Meanwhile, Nebraska Attorney General Jon Bruning announced this week that his office is suing the EPA over the power plant standards, arguing the rules overstep the agency's authority and will hurt Nebraska businesses.  

“The impossible standards imposed by the EPA will ensure no new power plants are built
in Nebraska,” Bruning said in a statement. "This federal agency continues to overstep its authority at the detriment of Nebraska businesses."

The Associated Press contributed to this report.