By Kevin Murphy
KANSAS CITY, Kansas (Reuters) - A recently enacted law in Kansas intended to block enforcement of federal gun regulations is unconstitutional, U.S. Attorney General Eric Holder wrote in a letter released on Thursday.
The law, which seeks to keep guns or ammunition from being subject to any federal regulation - as long they are kept in Kansas - directly conflicts with federal law, Holder wrote in the April 26 letter to Kansas Governor Sam Brownback.
"Federal officers who are responsible for enforcing federal laws and regulations in order to maintain public safety cannot be forced to choose between the risk of a criminal prosecution by a state and the continued performance of their federal duties," Holder wrote.
The law also bans federal or other agents from enforcing federal regulations in the making or sale of Kansas-made firearms.
Holder said a state "may not criminalize the exercise of federal responsibilities" and that all federal laws remain in effect.
Brownback, a Republican, signed the new law two weeks ago after it won overwhelming support in the state House and Senate. It took effect last week.
In a letter to Holder late Thursday, Brownback said the law has wide public support as well as bipartisan backing in the state legislature.
"The people of Kansas have clearly expressed their sovereign will," Brownback wrote. "It is my hope that upon further review you will see their right to do so."
The chief gun rights lobbyist for the law said Holder's opinion will not go unchallenged.
"We will stand our constitutional ground," said Patricia Stoneking, president of the Kansas State Rifle Association. "The federal government has far exceeded its boundaries for a long time and it is time to rein that in."
Stoneking said the Kansas law is patterned after one in Montana that is now being challenged in federal appeals court, and that similar measures are under consideration in many other states.
Kansas Secretary of State Kris Kobach said in a written statement on Thursday that the federal government cannot regulate guns that have never traveled in interstate commerce, such as those covered by the new state law.
Holder's office declined comment on whether other states have attempted to block federal regulation of weapons and ammunition made in their states.
(Editing by Brendan O'Brien, Edith Honan and Lisa Shumaker)