But a battle looms in the public sector, where unions are promising to fight a directive from the State Services Commission that government agencies include the trial provision in all contracts.
The Government last year passed major changes to employment law, including extending the 90-day trial to all employers and making union access to workplaces dependent on employer approval. The laws come into effect in April.
At present, the 90-day trial, which prevents newly hired workers from taking a personal grievance case for unjustified dismissal, is available only to employers with fewer than 20 workers.
But unions have been negotiating to protect their workers from the law by keeping it out of their collective contracts.
Agreements already in place include the Dairy Workers Union with Fonterra, the Tertiary Education Union with Victoria and Massey universities, and the Service and Food Workers Union with the TAB and some companies in the aged care and residential homes industries.
Last month, the State Services Commission made it clear to government agencies - including police, the fire service, and health and education sectors including teachers and doctors - that it expected the 90-day trial and union access rules to apply.
"The changes are government policy. Accordingly, state sector agencies are expected to implement them," wrote Peter Brown, deputy commissioner of state sector performance, in an email to government agencies last year.
The email, obtained by The New Zealand Herald, refers to the 90-day trial period and union access to workplaces.
"How you proactively use the new provisions is a matter to consider in the light of your own circumstances ... However, agencies should not `contract out of' aspects of the new provisions or contract to restrict any application of them," the email says.
Service and Food Workers Union national secretary John Ryall said district health boards were feeling the pressure.
"We've got 3000 members working in public hospitals. DHBs told us they don't want to change the status quo, but the Government expects them to implement government policy. We've told them that's not acceptable."
Public Service Association national secretary Brenda Pilott said employers were usually free to offer better conditions than the statutory minimum.
"The commission has taken a very hard line on this. They're saying that you must have these legislative minimums in your contracts. It's tying the hands of state sector employers.
"If there is an attempt to cement those [the 90-day trial and union access rules] into contracts coming up for negotiation, there will certainly be some stoushes."
It is thought that the trial period cannot apply to collective contracts unless the provision is explicitly written in the contract, but the law has not come into force yet and it has not been tested in court.
Employers can add terms and conditions on top of a collective contract, but they must be consistent with the collective agreement.
A spokesman for Labour Minister Kate Wilkinson said unions were free to negotiate as they pleased.
Council of Trade Unions president Helen Kelly said employers that tried to include the 90-day trial period in collective agreements could face industrial action.
"This is part of our campaign against the 90-day provision. All unions will be claiming [exemption from the trial period] in all collective agreements."
MAIN POINTS
• From April, the 90-day trial period will mean all new workers, regardless of the size of the employing company, can be dismissed and will not be able to take an unjustified dismissal case.
• Unions have successfully negotiated with employers, including Fonterra and Victoria and Massey universities, to exempt new workers from the 90-day trial period.
• The Government wants all new public-sector workers - from police to teachers to nurses to firemen - to be subject to the 90-day trial, but the unions are promising a fight.
