Democratic Gov. Beverly Perdue has vetoed a Republican-backed challenge to the federal health care overhaul that North Carolina’s attorney general argues is unenforceable.

Perdue announced Saturday her rejection of the measure, which attempts to block a provision requiring most people in 2014 to buy health insurance or face a penalty. The challenge was a GOP fall campaign platform plank.

Perdue had sounded willing to let the bill become law without her signature. She changed her mind when Attorney General Roy Cooper wrote that the federal law trumped state legislation and suggested the language could harm state health programs.

General Assembly leaders must decide whether to attempt an override. It’s Perdue second veto in under two weeks.