Gov. Bruce Rauner’s plan to ease air pollution rules for eight Illinois coal-fired power plants was rejected by a state panel that determined his proposal would put public health at risk.

Instead, the Illinois Pollution Control Board on Thursday proposed a different set of rules that would also relax existing limits on the release of toxins but not as broadly as what Rauner wanted.

The panel called part of the governor’s plan “inappropriate.”

The development does not resolve a long-running dispute over pollution limits that pitted health concerns against the financial stability of the downstate coal plants. But it does likely delay any final decision until after Election Day.

At issue are existing rules that direct energy producer Dynegy to operate its cleanest plants to balance toxins emitted by its dirtiest plants. The cleaner plants are outfitted with more sophisticated pollution controls, which makes them more expensive to operate.

Rauner’s Environmental Protection Agency asked the board to scrap that mandate and replace it with one that imposed an annual cap on total emissions from all eight plants in central and southern Illinois. Critics said that would result in greater amounts of toxins released into the air.

The pollution panel agreed to do away with the directive on Dynegy’s cleanest plants. But it also said the air pollution caps sought by Rauner’s EPA were too high.

The board is proposing lower total emissions of sulfur dioxide and nitrogen oxide than what the governor proposed. It also said those toxin limits should be lowered still more for Dynegy’s fleet in Illinois if the company decided to shut any of the eight coal plants.

Health and environmental groups opposed to Rauner’s rule change had a lukewarm reaction to the pollution board’s proposed alternative.

“It’s less bad than what was out there but it looks like it still is going to make air quality worse,” said Brian Urbaszewski, director of environmental health programs for the Respiratory Health Association in Chicago.

Specifically, the move to an overall cap doesn’t protect local communities from increased pollution. He cited the Edwards coal plant near Peoria.

“It’s a step in the right direction,” he said. “Unfortunately, they’re still leaving a lot of people behind.”

The board will hold a public hearing later this month on its proposal, giving advocacy organizations and Dynegy a chance to retool their arguments.

A spokeswoman for Dynegy’s Texas-based corporate parent, Vistra, said company officials are reviewing the proposal. Illinois EPA Director Alec Messina also said he needed more time to review it.

A spokeswoman for Rauner said the decision reflects the independence of the pollution control board. Rauner appointed all but one of the panel’s five members.

“The governor’s office recognizes the critical importance of the board’s independent functioning, and supports solutions that promote environmental friendliness, regulatory certainty and a pro-growth business environment,” Rauner spokeswoman Beth Tomev said in a statement.

The Sierra Club said in a statement that the pollution board “delivered a vital check” to Rauner and called the governor’s proposal a “backroom coal bailout.” The environmental group said it hopes the board will consider poor minority communities affected by Dynegy plants as it completes its rule-making process.

“The board is seeking to establish a cap that is a reasonable compromise and still has some meaning to be a regulation that helps control the pollution from Dynegy’s coal plant,” said James Gignac, an analyst with the Union of Concerned Scientists.