WASHINGTON: President Barack Obama's plans to curb the gases blamed for global warming are heading to their first test, a House hearing in which administration officials make their case before skeptical lawmakers.

The energy panel meeting Wednesday comes just days before a deadline for the Environmental Protection Agency to release a revised proposal setting the first-ever limits on carbon dioxide from newly built power plants.

The rule, which will ultimately force the EPA to tackle emissions from existing power plants as well, is a key component of Obama's strategy to tackle climate change. It is also one of the most controversial, since addressing the largest uncontrolled source of carbon pollution will have ramifications for the power sector and everyone who flips on a light switch.

"Like the president has said, we have a moral obligation to act on climate change and we are using the tools at our disposal to get it done," Heather Zichal, deputy assistant to the president for energy and climate change, said in an interview with The Associated Press.

The coal industry and its allies in Congress have been quick to criticize the regulation in advance of its release, saying it will raise electricity prices and the cost of producing power, particularly from coal.

Coal, which supplies nearly 40 percent of U.S. electricity, has been struggling to compete with natural gas, which has seen historic low prices in recent years thanks to a boom brought on by hydraulic fracturing. "We will not turn a blind eye to efforts to impose back-door climate regulations with no input from Congress," Sen. Lisa Murkowski and Rep. Don Young, both Alaska Republicans, wrote in a letter to Obama on Tuesday.

The proposal has been in the works for more than a year and stems from a 1970 law passed by Congress to control air pollution. In 2007, the Supreme Court ruled that that law, the Clean Air Act, could be applied to heat-trapping pollution.

The latest version of the power plant proposal, which updates one released in March 2012, is likely to be more lenient on coal-burning plants than it was initially, but it will still make it very difficult for energy companies to build new coal-fired plants in the U.S. New natural gas power plants will also be covered, but they will be able to meet the emissions standard more easily.

For coal-fired power plants, the new proposal will eventually require the installation of technology to capture carbon and bury it underground. Not a single power plant in the US has done that, largely because it has not been available commercially and, if it were, it would be expensive.

The administration has $8 billion to dole out in loans to mitigate the cost of developing the technology. But even Energy Secretary Ernest Moniz has said that "it's not going to happen tomorrow," but sometime in this decade.