Mrs Mackintosh said her school had more students with highly specialised needs - "our treasures" - than most.
The school employed 23 teacher assistants to support those students and received government funding per student.
Last year the school's board topped that funding up to the tune of $170,000 from the school's operational grant, Mrs Mackintosh said.
It was necessary to meet students' needs and pay staff fairly.
Teacher assistants carried out skilled work, helping students learn in spite of serious physical, mental and emotional learning challenges, she said.
There were children who needed help eating and going to the toilet.
"Our teacher assistants go above and beyond and do it cheerfully. They are skilled, empathetic, caring and nurturing."
She said if the Government increased support staff pay without increasing operating grants, the school might have to cut hours or jobs.
Gate Pa School principal Richard Inder had the same concern.
"So, for example, they might get a 3 per cent pay rise, but our operational grant is only going up 1.3 per cent, so we're out the door before we even start."
At his school, teacher aides ran reading and writing programmes, working with students in small groups. They also worked with students one-on-one, carrying out individualised learning plans.
He had seven on his staff but would need almost twice that to put one in every classroom.
"They are a very vital part of our school staff for the many ways they support children's learning. They are highly valued but their wages do not reflect that."
Fairhaven School principal Paul Hunt is a member of the Educational Institute's principals' council.
He said most support staff were paid $16 to $20 per hour.
They worked school hours, 9am to 3pm, and weren't paid over holidays.
"It's not a lot to live on," Mr Hunt said.
Education Minister Nikki Kaye said pay increases had been offered in past years.
"The Ministry of Education and NZEI are currently in negotiation through collective bargaining around pay increases. Over recent years this process has led to increases of up to 1.5 per cent each year," she said.
She said it was important to not look at the issue purely in terms of the 2017 Budget.
Operational grants had cumulatively increased 16 per cent between 2010 and 2016.
"This means that boards of trustees have been resourced to be able to support pay increases. Pay increases are wider than just operational grants. For example, we have the funding review currently taking place which is looking at potential changes to the way schools are funded," Ms Kaye said.
Signatories
Some of the Bay of Plenty principals who signed an open letter to the Government calling for a fair end to support-staff pay negotiations.
Fiona Hawes, Tauranga Primary School
Vicki Knell, Omokoroa Point School
Ben Fuller, St Mary's School, Tauranga
Shane Cunliffe, Te Puke Primary School
Richard Inder, Gate Pa School
Neil Towersey, Te Puna School
Shelley Blakey, Arataki School
Paul Hunt, Fairhaven School
