TOPEKA, Kan. (AP) – Opponents of a coal-fired power plant in southwest Kansas are asking the Kansas Supreme Court to overturn a state permit for the project.

The Topeka Capital-Journal reported Monday that Lawyers for Earthjustice and Sierra Club filed a brief with the court alleging that the air permit granted to Sunflower Electric Power Corp. did not comply with federal air safety regulations.

Sunflower plans to build the controversial $2.8 billion coal-fired plant near Holcomb. The Kansas Department of Health and Environment issued the permit in December.

A Sierra Club spokeswoman says the permit process was hijacked by coal plant supporters.

Sunflower and state health officials have consistently said the permit process was valid.