The Post Primary Teachers Association says the education of students at a new charter school - which was not properly set up - is suffering because they're unable to settle in.
Te Kura Hourua ki Whangaruru was built from scratch on a farming block, and wasn't fully completed before the start of term one in February.
The school's website says bad weather delayed the building project, and also prevented furniture from being set up in classrooms.
Staff were also forced to develop an alternative programme for the second week.
Post Primary Teachers Association president Angela Roberts says the incomplete set-up would have disrupted students' learning and settling in to their new classroom environment.
In order for students to thrive, Ms Roberts says they need a good learning environment.
She says the staff would have struggled to provide that because of set-up problems being rushed through.
The school's principal, Natasha Sadler, was not available for comment.
Te Kura Hourua ki Whangaruru website lists the buildings that had not been finished by the start of Term One as the assembly hall and administration block.
The Ministry of Education has admitted the school has experienced some challenges since opening.
It is having to arrange to fill subject gaps by providing students with some correspondence school lessons and teaching through Northland Polytechnic.
The Ministry of Education is downplaying the school's problems and says it is not unusual for some new schools to encounter difficulties after opening for the first time and that plans are in place to resolve them.
The ministry has confirmed that Te Kura Hourua ki Whangaruru has arranged to supplement its teaching by providing students with correspondence school lessons and teaching through Northland Polytechnic.
The kura, situated on a 200-acre farm, has placed an advertisement in the Education Gazette offering vacancies for three teachers.
Education Ministry acting head of sector enablement and support Jill Bond concedes the school has experienced some challenges since opening.
Ms Bond says it had five fulltime teaching staff, but since then one of the fulltimers has left, leaving four teachers and the school is seeking two fulltimers and one part-timer.
She is defending the school's start, saying it is not unusual for some new schools to encounter difficulties after opening for the first time.
New Zealand First's education spokesperson Tracey Martin says she raised concerns last year in Parliament about whether the school would be ready to open for the more than 70 students it was intending to take.
Ms Martin says she feels that her concerns have come to fruition and it was impossible for the staff and board to succeed, given the limited planning time to set up the school.