TOPEKA, Kan. (AP) -- The chief sponsor of a bill that could imprison federal officials for enforcing federal gun restrictions in Kansas says an assistant attorney general's criticism of the measure is off-base.

The Lawrence Journal-World (http://bit.ly/YrObOG) reports Assistant Attorney General Charles Klebe asserted the Supremacy Clause of the U.S. Constitution can't be waived by state law.

He also says a provision in the measure prohibiting doctors other than psychiatrists from asking about gun ownership could face First Amendment challenges.

But Shawnee Republican Rep. John Rubin says Klebe's assessment is "dead wrong" because the Supremacy Clause doesn't apply to unconstitutional federal laws.

A fiscal note attached to the bill estimates the measure would result in multiple lawsuits that could cost the state $825,000 over three years in legal expenses to defend.