Topeka — Legislators who support two proposed coal-fired power plants in southwest Kansas argue that a regulator's decision to block their construction also endangers existing plants that supply most of the state's electricity.

They're using that argument to justify seeking limits on the secretary of health and environment's power to impose new pollution standards. The limits are part of energy legislation that would overturn Secretary Rod Bremby's denial of an air-quality permit for the Holcomb plants.

A permit for Westar Energy Inc., covering three coal-fired plants at its Jeffrey Energy Center, expired Jan. 27. State law allows Westar to operate the center, about 30 miles northwest of Topeka, while Bremby decides whether to renew its permit, but the Department of Health and Environment expects to take public comments this spring.

The permits for 13 other coal-fired plants, operated in seven counties, also expire before the end of September.

Bremby appears likely to face criticism no matter what he does. Legislators don't think he'll shut the plants down because they're crucial to the state's power supply. But they wonder whether he will try to force utilities to limit their carbon dioxide emissions. If he doesn't, his critics contend, he's discriminating against the proposed southwest Kansas plants.

"The people who have the permits that are going to be considered want to know what the rules are going into it," Senate Utilities Committee Chairman Jay Emler, a Lindsborg Republican, said Wednesday. "What are the rules?"

Sunflower Electric Power Corp. wants to build the new plants next to one it operates in Finney County. The Hays-based utility's $3.6 billion project has bipartisan support among legislators.

But in denying Sunflower's permit, Bremby cited the plants' potential carbon dioxide emissions and said the state couldn't ignore the potential dangers of global warming, which many scientists have linked to greenhouse gases such as CO2. The plants could produce up to 11 million tons of CO2 a year, though Sunflower officials believe actual emissions could be as little as 4.5 million tons.

Bremby has said there is a distinction between renewing permits for existing plants and allowing new sources of CO2 emissions.

As for regulating CO2, KDHE spokesman Joe Blubaugh said: "We're going to work with industry to come up with voluntary reductions."

Both chambers have approved bills that would allow Sunflower to reapply for its permit, under rules requiring Bremby to approve it. Both bills also would prevent Bremby from imposing air-quality standards stricter than those imposed by the federal government without legislative approval.

The state has never regulated CO2 emissions, and Bremby wouldn't be allowed to do so under either bill until federal regulations are enacted.

Three House members and three senators, including Emler, will draft the final version of a single bill, but they've made little progress in two rounds of talks this week. They hope to resume negotiations today.

In her strongest statement to date on legislators' work, Sebelius said she opposes both chambers' measures.

"Both have elements which I find to be totally unacceptable, starting with stripping a Cabinet secretary of the statutory authority to do his job," Sebelius said during a Statehouse news conference.

Sebelius and some legislators have said the state needs to move away from its heavy reliance of coal-fired plants for its electricity and encourage the development of wind farms. According to U.S. Department of Energy figures, Kansas gets about 75 percent of its power from coal-fired plants.