New today: Renewables and natural gas groups are warning Energy Secretary Rick Perry that invoking emergency powers to prop up coal-fired and nuclear power plants would be illegal.

"There is no emergency or threat to the national defense on which the Department could lawfully base the exercise of its emergency authorities," per a new letter.

Quick take: The dense 12-page letter from 6 trade groups often reads like a court brief. It's a preview of litigation that would greet attempts to save economically struggling plants that could close in coming years.

The context: DOE is weighing a request from FirstEnergy Solutions to invoke emergency authority under the Section 202(c) of the Federal Power Act to bolster ratepayer revenues for coal and nuke plants in the PJM region... It also warns that DOE would lack legal justification to use its powers under: the Defense Production Act of 1950 (to ensure supply of critical industrial materials for security needs) and the 2015 addition to the Federal Power Act, Section 215A (to protect critical infrastructure and address a "grid security emergency.")

See the full Axios news brief (Item #4) that lists all signatories, including AEE, here.

Other related stories: E&E News Energywire's "Strange bedfellows lobby Perry on coal plant subsidies" is here, and RTO Insider's, "Six Groups Send DOE Letter Opposing Use of Emergency Authorities" is here.