A universal gun background check measure, approved by Nevada voters and touted as a victory by gun control advocates, was supposed to take effect after the clock struck midnight Saturday and residents rang in the new year.

But the FBI and Nevada’s attorney general, calling the initiative unenforceable, have put it on hold indefinitely.

The unexpected development is a welcome surprise for Second Amendment supporters, who have long been critical of such background check efforts funded by Michael’s R. Bloomberg’s gun control advocacy group, Everytown for Gun Safety.

“When you have folks who don’t know what they are doing and don’t know what they are talking about when it comes to firearms policy, this is the sort of mess that you wind up with,” said Craig DeLuz, a spokesman for the Firearms Policy Coalition. “An idea that sounds good on paper can end up violating the rights of citizens.”

At issue with the Nevada ballot initiative, which 50.4 percent of voters approved on Nov. 8, is who would be responsible for conducting background checks during gun transactions between private citizens.

Transactions between private citizens previously did not require any background checks. Under the initiative, transactions are subject to federal screenings through the FBI-run National Instant Criminal Background Check System.