Stein and fellow Democrats argued the bill cracks down on voting rights.
Republicans said House Bill 958 is necessary to improve election security and efficiency.
"People like you power our democracy, I know it, you know it, and the general assembly knows it, and that's why legislators are trying to make it harder for you to vote and for your vote to count," Stein told a group of supporters.
The NCGOP rejected that notion, telling ABC11 in a statement that "Just like voter ID, basic safeguards, transparency, and independent oversight give North Carolinians greater confidence that our elections are being administered fairly and securely. If Gov. Stein is genuinely concerned about election integrity, he should welcome independent audits - not veto them."
The bill would shorten primary early voting, give the state auditor authority to conduct independent post-election audits and require military personnel serving abroad to mail a photocopy of their photo ID.
"This damaging bill eliminates a week of early voting in the primary, invites sore losers to try to overturn general elections by throwing out people's votes after the race is over, and sows distrust in our elections," Stein said. "Instead of trying to undermine our democracy to cling to power, the legislature should focus on improving people's lives and winning elections fair and square."
North Carolina House Election Law Chair Hugh Blackwell, R-Burke, accused Stein of putting politics before election integrity.
"House Bill 958 continues practical election reforms, so we all can have greater confidence that every lawful vote in North Carolina is counted fairly and accurately," Blackwell said. "Gov. Stein's veto of this legislation puts politics ahead of common sense, and the peace of mind voters should have when they cast their ballots."
HB 958 passed on an entirely party-line vote, meaning that if those numbers hold, Stein's veto could be sustained.
Even if Republicans override Stein's veto, the bill's changes would not go into effect for November's midterm elections.
SEE ALSO | More NC Politics News
Download the ABC11 News app