Women make up 98 per cent of early childhood teachers and 92 per cent of the 11,754 teacher aides in the 2013 Census.
NZEI president Lynda Stuart said the agreement to start pay equity talks for the teacher aides depended on staff voting over the next few weeks for a draft settlement which includes only modest immediate pay rises of up to 1.6 per cent this year and 1.2 per cent next year.
"The actual collective agreement amount is not a high level, and it's not being funded to the schools, so the big prize for support staff is pay equity," she said.
The draft agreement, signed by Ministry of Education advocate Nick Kyrke-Smith, states: "The parties and NZ School Trustees Association will participate in a pay equity process covering the work of teachers' aides."
"This process will follow the Government's recently announced principles for addressing pay equity claims, together with further details agreed between the parties which will form the terms of reference for this process," the agreement states.
"The terms of reference will be agreed within one month of signing the terms of settlement and participation in the pay equity process will commence from the date these terms of reference are agreed."
Stuart said the timeframe was subject to negotiation, with the union pushing for quick agreement in four months while the ministry was offering a process that might take 18 months.
Most teacher aides earn between $17 and $20 an hour. The precedent-setting caregivers' deal will lift wages for home and community support workers with at least eight years' experience from a current average of $16.22 an hour to $21 from Saturday and $25 by July 2021.
The caregivers' deal was tied to the workers' qualifications, and Stuart said the talks for teacher aides would involve developing more systematic training for them.
"There are some one-off courses for them. Some universities do run support staff courses, and you also have some online courses that people can do, but they are not systemic," she said.
She said the proposal for a pay equity claim for early childhood teachers was at a much earlier stage because the claim is aimed mainly at private and community-owned childcare centres which are largely non-unionised.
"We have got an online page that people can sign up into," she said.
"This is a process that we want to start. We know that there are about 20,000 people involved. We know that for the unqualified there is the potential of there being a shift that is like the caregivers, 20 to 40 per cent. But we don't know all the details around their pay simply because they are not unionised."
Early Childhood Council chief executive Peter Reynolds said employers would support the claim as long as the Government funded it.
He said the employers were already lobbying the Government to restore a pre-2011 policy of passing on any pay increases for the country's 3800 kindergarten teachers, who are part of the state sector, to the 24,000 teachers in private and community-owned centres.
Kindergarten teachers have won four pay rises since 2011 and now earn between $2000 and $9000 a year more than teachers with the same qualifications in private and community centres.
