Oklahoma Attorney General Scott Pruitt has asked a federal judge to strike down a regulation that is part of the federal health care overhaul law.
Pruitt filed a motion late Tuesday in U.S. District Court in Muskogee that challenges the Affordable Care Act.
The IRS wants to assess large employer penalties in states like Oklahoma that did not establish state health care exchanges.
Pruitt says that contradicts the law's language.
Pruitt is strongly against the idea that would fine large employers, including local and state governments.
Last year, U.S. District Judge Ronald White rejected assertions by government lawyers that Oklahoma lacked legal standing to challenge implementation of the health care law.