Kevin McIntyre, the newly sworn-in chairman of the Federal Energy Regulatory Commission, has told Energy Secretary Rick Perry it needs a 30-day extension before it can rule on his proposal to subsidize coal and nuclear plants.

“The commission has sworn in two new members within the last two weeks,” McIntyre wrote to Perry in a letter addressed Thursday. “The proposed extension is critical to afford adequate time for the new commissioners to consider the voluminous record and engage fully in deliberations.”

McIntyre, a Republican nominee of President Trump, was sworn in as chairman on Thursday, which gave the FERC a full slate of five members for the first time in two years. Another new commissioner, Richard Glick, a Democrat nominee of Trump, was sworn in Nov. 29.

Perry expected the commission to rule by Dec. 11 on his proposed rule for FERC to pay ailing coal and nuclear plants to keep running for the “reliability and resilience” they provide to the power grid.

McIntyre said in his letter that FERC has received more than 1,500 comments since soliciting public response on Oct. 2.

Perry’s plan would rewrite the rules governing wholesale power markets to reward power producers that are able to store enough fuel for 90 days of generation on-site, a condition coal, nuclear and some hydropower plants can fulfill. It is intended to reward coal and nuclear for their ability to keep the lights on when the grid is significantly strained.

Cheaper, cleaner natural gas has replaced coal at power plants around the country, and now supplies more than a third of the nation’s electricity, while renewables have become increasingly competitive.

But the wider energy industry, from oil and natural gas producers to wind and solar, opposes the proposed rule and said it would upend competitive power markets by propping up failing plants and increasing prices for consumers. FERC, which is independent, has the authority to approve, modify or outright reject Perry’s plan.

McIntyre and Glick’s position on FERC is seen as key in figuring how the commission votes on the proposal. Neil Chatterjee, a Republican who served as chairman on an interim basis but remain on the board, has expressed strong support for adopting the proposed rule in some form.

McIntyre and Glick, however, stressed in their September confirmation hearings that they would adhere to the commission's basic duties of approving and regulating the interstate transmission of electricity, natural gas and crude oil, without favoring one energy source over another.

The other FERC members, Robert Powelson, a Republican former Pennsylvania energy regulator who joined the board this summer, and Cheryl LaFleur, a Democratic holdover from the Obama administration, have reacted more skeptically to Perry's plan, vowing to maintain the board’s independence.