"From the beginning of this process we've been clear that to attract and retain teachers we need to be paid fairly and have the time and support to ensure every child gets the best possible education," Stuart said.
"While the latest offer for teachers included a total salary increase of approximately $9500 - $11,000 over three years, it failed to address the important issues of time and class size, which underpin the crisis in education.
"Disappointingly, we end this year without the necessary movement from the Government, and with still not enough to meet the needs of children, schools and teachers."
Stuart said the union had informed the Ministry of Education and Education Minister Chris Hipkins of the outcome of the ballots, and would seek further negotiations immediately, requesting a new offer by early in Term 1 next year to bring back to members.
The ministry's education secretary Iona Holsted said despite the rejection they remained committed to continuing bargaining in good faith and minimising any further disruption for students' learning and parents.
"It is only by negotiation we will settle this long-running dispute," Holsted said.
"We now invite NZEI to return to the bargaining table to discuss options for settling the collective to meet their member's priorities within the $698 million package."
Holsted said the $698m package, which followed bargaining in November, had been described by the Employment Relations Authority as "handsome and competitive".
"The authority also acknowledged the commitment of the Government to working with teachers to gradually address the sector's needs. This includes the current activity on workload and supply."
Holstead said the Government was addressing workload concerns by spending an extra $500m for learning support, providing $40m to boost teacher supply in the short to medium term, developing a long-term Education Workforce strategy, work to reduce administration tasks, and rolling out an Education Professional's Well-being Framework.