The government said it will investigate the use of fixed-term contracts in schools "as a matter of urgency."

Education Minister Chris Hipkins said the number of such contracts is an area of concern.

It comes after reports from school unions and teachers that some schools are allegedly "trying before they buy" through their use.

The number of beginning teachers entering the workforce in permanent positions has dropped. Half of all new secondary teachers last year were put on fixed-term contracts, 23 per cent were on permanent contracts and 27 per cent were in relief roles, according to a secondary teacher supply report from August last year.

The Employment Relations Act states employers must have a genuine reason based on reasonable grounds to use a fixed-term contract, and must state when and why the employment will end. Establishing the suitability of an employee is not a genuine reason. Maternity leave, study leave, secondment and specified projects are examples of genuine reasons.

The report states the high rate of non-permanent appointments 'may increase the attrition rate of new teachers to the profession.' Nearly half of all new secondary teachers leave within five years, it said.

"It means they're not getting off to a good start with their teaching careers, it means they're not getting the professional support and mentoring that they should," Mr Hipkins said.

He said a lot of work was needed to improve the transition between teacher training and school, noting the importance of making changes when the country has a teacher shortage. Work is already underway to improve the situation for beginning teachers, he said.

NZSTA hopes review will improve situation

NZSTA president Lorraine Kerr said there were a few schools the membership-based organisation would like to investigate, but said it's hard to know how wide the issue of unjustified use of such contracts is as it only provides advice and services to boards that make contact, in most cases.

"We do need to practice what we preach, we need to get a picture of what's going on in our schools," she said.

She said the organisation would join with other sector groups to undertake a review on the issue, which would see a survey given to all schools next year.

The primary and secondary unions, NZEI and PPTA, take on disputes for teachers where they believe there are grounds for fixed term-contracts to be illegal. PPTA has 60 to 70 cases a year and NZEI has 10 to 13 at any one time, representatives said.

Both unions said the number of unjustified contracts is likely to be higher as some teachers don't want the union to take the dispute up or don't raise the dispute with them in the first place.

1 NEWS spoke to a number of teachers and teaching students who were not aware their fixed-term employment or future fixed-term employment had to have a genuine reason to be legal. Some accepted the practice, even if unjustified, as the only way to advance in their career or future career.

"Anything that is a barrier that gets in the way of getting great people into the profession and getting them started and being teachers is a problem," PPTA president Jack Boyle said.

NZEI has a commitment for schools to pledge they will support new teachers and never use fixed-term contracts illegally, called the Beginning Teacher Charter. PPTA has an equivalent in The Promise to New Teachers, which nine schools have signed up to.

"You can't use it as a de facto way of trying before you buy" - employment lawyer

Employment lawyer Main Chen said the use of unjustified fixed-term contracts was not good for the profession.

"What I've heard anecdotally is that teachers are leaving the profession because they don't feel they've got job security so look it's never in the public interest to breach the law, break the law and this is the reason why - we need teachers."

Ms Chen said while she was at a loss to how schools were using unjustified contracts, she said it wasn't surprising as boards may not have the funding to seek legal advice and are usually made up of parents that may lack employment law knowledge.

"This is a situation where the law is clear and school boards of trustees and principals who are ultimately the employer here need to comply with the law."

PPTA president Jack Boyle said a common reason given for fixed-term contracts by schools, roll fluctuation, is not a justification for their use. Ms Chen said if a school's roll number did drop, they could consider making staff redundant.

Ms Chen said she has to recite the law to employers who call asking how to put potential staff on fixed-term contracts after having a bad experience with an employer that didn't perform in their role.

She said teachers should be well-informed about their rights, with schools more likely to change their actions if questions are raised.

"Somebody has to take them on otherwise they'll continue to do it."

Limbo for teacher

Auckland secondary teacher Guy Wilson says he has experienced questionable fixed-term employments before becoming a permanent teacher.

"The reasons given... were really vague. It's always concern around roll growth for students but there wasn't any concern that I was seeing in practice," he said.

After one fixed-term rolled into another new contract the following year, he attempted to negotiate but the situation didn't change, he said. The union advised him of his rights and that's when he realised the situation wasn't legitimate. Questionable contracts are widespread, he said, describing the situation of one colleague that was let go after raising concerns of being made fixed-term three years in a row.

During his time as a fixed-term teacher, Mr Wilson took class subjects outside his English qualification and moved multiple times. He said he was unable to focus on teaching and that it made renting the only option, made him worry about money over holidays and future employment at the end of year and strained personal and professional relationships.

"You don't really end up feeling part of the school culture itself properly... If feels a bit like being in limbo," he said. He considered leaving teaching.

Mr Wilson said he didn't receive any education around employment rights when entering the profession during his tertiary study and only learned about his rights from PPTA education sessions.

"Beginning teachers particularly are in a really tough position for negotiating their contracts when your registration is determined by your principal, and they're the ones making you the offer... They're taking advantage of that gap in that knowledge," he said.

Schools have to manage funds carefully - principal

Secondary Principals' Council chair and Darfield High School principal James Morris said new teachers are in a vulnerable position.

"You don't sort of want to start pushing some issues that might make you less likely to get a job," he said.

He said roll growth is a genuine reason but questions and research are necessary to "determine how close that is to a reality."

As far as the council is aware principals are complying with the law, but he said it's hard to know when individual schools are pushing the boundaries into illegal behaviour.

It's an issue to the council and it wants to make sure new teachers are being treated fairly, he said.

Mr Morris said a key reason for fixed-term use is schools' obligation to stay afloat financially.

"A lot of secondary schools employ more teachers than their basic staffing allowance entitles them too. It means that anybody over the entitlement, they have to be very careful of because if they don't have the money to pay for it then there are issues if the roll starts dropping," he said.

He said he believes the teacher shortage will make principals more likely to offer permanent positions despite being nervous that it puts them at risk.

Teaching organisations are welcoming the Education Gazette advertisement addition that allows schools to specify why a role is fixed-term. A Ministry of Education spokesperson said this was changed to encourage correct employment practice.

Some advertisements don't specify a reason though.

A PPTA spokesperson said of the 173 secondary fixed-term positions advertised on one day last month, 90 were for reasons they claim are legitimate and 83 were for reasons they claim may or may not be legitimate.