Up to 10,000 teachers, children and parents are expected to march up Auckland's Queen St tomorrow in the first strike by primary teachers for 24 years.
Teachers led by NZ Educational Institute president Lynda Stuart will assemble in Fort St at 11am to march up Queen St to Aotea Square for a noon rally.
"There will be thousands. I'm thinking 5000, 6000,7000, a very big crowd," Stuart said.
About a third of the union's 29,000 primary teacher members live in the Auckland area, with buses planned to bring teachers in from Ōrewa and a train coming in from Pukekohe.
Thousands are also expected to turn out in Wellington, gathering at the Westpac Stadium at 11am and marching to Parliament for a midday rally led by NZEI principals' collective agreement negotiator Louise Green.
In Christchurch, teachers will meet in four designated areas and bus into Cathedral Square at 11am, then march around the city and back to the square to hear the lead negotiator for the teachers' collective agreement, Liam Rutherford.
It will be only the third time primary teachers have gone on strike in the union's 135-year history, after a 1991 strike in the year of the Employment Contracts Act and a 1994 strike which achieved pay parity with secondary teachers.
"That shows that we don't do this lightly," Stuart said.
"This is about not having enough teachers in this country to meet the needs of children because we don't support our teachers properly.
"We have a real under-investment in education at the moment and we can't attract people into the profession, and if we do, they leave after a few years. This is a crisis heading for a disaster."
Teachers beginning with a degree and a teacher's qualification currently start on $49,588, just below the national median wage of $49,868. Twenty years ago they started on 15 per cent above the median wage.
Teachers at the top of the basic pay scale, reached after seven years' experience, earned 75 per cent more than the median wage in 1998 and now earn only 52 per cent above the national median.
The union is claiming a $296 million, 16 per cent pay rise over two years that would take the top of the basic scale up from $75,949 to $88,100.
Other claims include reducing the teacher:student ratio in Years 4 to 8 from 1:29 to 1:25. The Ministry of Education says these non-pay-related claims would cost a further $291m a year on top of the extra $296m a year for salaries.
Stuart said she would start the day at 8.30am tomorrow with other teachers on a roundabout at Blockhouse Bay, one of many similar events planned around the country.
She said children and their parents, many of whom plan to take a day off tomorrow for child-minding, would be welcome at all events.
"Parents are saying, what can we do, and I'm telling them you would be welcome, absolutely," she said.
"It will be our parents, and in some cases where schools are closed our support staff have been given an option so our support staff are willing to join us for this.
"These are whole communities that are stepping up and supporting us. It's exceedingly humbling to see this."
Auckland Transport spokesman Mark Hannan said there were no plans to close Queen St but staff would operate traffic lights manually to let the march pass.