A Rolleston College student wept as she told Education Ministry staff that classes are held in corridors because the school is bursting at the seams.
A community meeting was held in the Canterbury town on Wednesday night to discuss the ministry's decision to strip back plans for its second campus - even though construction is already under way.
More than 2000 had signed a petition opposing the decision and Rolleston College said it had received more than 100 letters of feedback from those in the school community.
Head student Mackenzie Wills broke down as she revealed the impact the school's rapidly growing roll was having on her education.
"I have experienced sitting in hallways, learning in science classes for classes that are not science. I have experienced so much overcrowding - being put in small, confined spaces with 60 learners. It's not been an ideal experience," she said.
The current campus would be able to cater for 1800 students when construction finished later this year.
But the school's already at that number.
"I have a younger brother and younger cousins who are intending to come to Rolleston College and it makes me mad that it's going to affect them in such a negative way," Wills said.
A secondary campus two kilometres away has had its site works completed - but two weeks ago, the Ministry of Education stripped the designs back.
It removed counsellors offices and pastoral care, gym changing rooms, a sports office, staff room and a basketball court.
Parent Paul Taylor has two daughters at the school and said it was heartbreaking.
"Everything in the plans is what they need. It's not something flash they dream of, it's what they need," he said.
"And we know with students nowadays how they need counselling for the future and to keep them on track. Life's not as simple as it used to be and to take all that away - where are they going to end up when they leave school?"
He planned to organise a march from the school to the local MP Nicola Grigg's office.
Rob Hunt also has children at Rolleston College, with one more due to start in two years' time.
He is the board chair of West Rolleston Primary - which had seen its roll go from 47 students to 840 in just eight years.
"We're in a position where Rolleston has not had its own high school until about four or five years ago when this wonderful kura was built," he said.
"But previously children would travel to either Lincoln or to Darfield. Lincoln I hear is going through similar struggles with its growth and certainly that is something I can believe looking at our own community - this is something the Ministry has to deal with."
Temporary classrooms, like the 21 on Rolleston College's first campus, made learning harder, tumuaki principal Rachel Skelton said.
They were not always fit for purpose and sat on carparks, green spaces and sports courts.
"[The Ministry of Education representative] is right, it's not just about buildings, it's about what happens within them, but I don't think setting up a new school without the essential facilities that you would find in any secondary school in New Zealand is the way to go," she said.
The cuts were unfair, Skelton believed.
"I really implore the government to think about where are other ways that you could save money that don't directly affect children. There's got to be other places where money can be saved rather than things that interface with kids. It seems an odd area to focus on."
Ministry of Education representatives at the meeting told the 150 people gathered that the cuts were down to funding.
They confirmed the second campus would have 23 classrooms in the first phase, and estimated 12 to 16 temporary learning spaces would also be needed.
The representatives said they would meet with school staff and the board next week for further discussions.
Those at the meeting declined RNZ's interview request.
Future development 'subject to funding' - ministry
In a statement, Ministry of Education head of property Sam Fowler said the school was told of its revised first stage proposal for the project in February.
"We understand the school and community is concerned that the project will be staged and some facilities will be temporary. We will continue to work with the college to refine the proposals in order that they support their educational and operational needs."
Fowler said the ministry was investing more than $50 million in the first stage of development at Rolleston College's second campus.
"This will deliver a new STEM block, a single-court gymnasium and 12 to 16 temporary classrooms. This will allow for a roll of approximately 650. It is expected these works will be complete for the start of the 2026 school year.
"Further stages of development will continue to grow the campus over time as the college roll grows. The timing of the delivery of those stages will be subject to the funding we receive through future Budgets."