The scheme lets employers take on new workers for up to 90 days. If the worker is sacked within that period, they cannot raise a personal grievance for reasons of unjustified dismissal.
The 90-day trial scheme is now only available to companies with up to 20 staff, which affects about 30% of the workforce, but One News reported last night the Government will open the scheme to all companies.
It is also looking to allow employers the right to deny access of unions to the workplace on reasonable grounds, prospects the Labour Party and unions say are an attack on workers' rights.
Union leaders vowed to fight the changes and Labour leader Phil Goff promised to repeal the 90-day trial scheme altogether when Labour regains power.
Prime Minister John Key is expected to flag changes to the Holidays Act and the Employment Relations Act in a speech tomorrow at the National Party annual conference.
Changes to the Holidays Act may mean workers can trade holidays for cash.
A spokesman last night would only say the announcement will be "on some fair and balanced changes to labour laws".
Earlier, Mr Key told One News the 90-day trial, which began last April, had been a huge success.
"The results of those have been stunning. It's ensured that a lot more New Zealanders had the opportunity to engage in work. Employers have been willing to take the risk."
Labour Minister Kate Wilkinson earlier told One News the Government was looking to empower employers with regard to union access.
"The employer should be in charge of the workplace, but we still want good faith to remain and we still want the employer to have reasonable grounds to withhold consent. We doubt that will happen very often."
Council of Trade Unions president Helen Kelly said a clause of reasonableness was meaningless.
"We've operated under that sort of provision before. The employer says, `You can come in but you have to wait three hours', or 'you can come in tomorrow'. They just stuff you around and use it as a tactic.
"The reduction in union access is outrageous and is a direct attack on us."
She said the CTU had represented about 10 workers in contesting dismissal under the trial, but many more had lost their jobs under the scheme.
Earlier this year, the Employers and Manufacturers Association (Northern) said the trial scheme was working well.
Business NZ chief executive Phil O'Reilly said the trial period for small businesses had been an "outstanding success" because it "de-risked" the process of employment.
Mr O'Reilly said while it was different for bigger companies, they also faced issues with employing staff and expanding the trial period to them would affect their employment decisions.
"No matter how wealthy they are, nobody wants to take on the risk of a personal grievance because it's not just a cost issue. It's corporate reputation issues and a whole bunch of other things."
But Labour leader Phil Goff said extending the scheme was "absolutely unnecessary" and would mean the axe would hang over new workers from day one, "regardless of whether they are up to the job".
Engineering, Printing and Manufacturing Union national secretary Andrew Little was "outraged".
"The protection against unfair dismissals is fundamental. Youth unemployment has risen, so the argument that this sort of thing creates jobs is complete rubbish."
POSSIBLE CHANGES
• Extending 90-day trial scheme, where employees can be fired and cannot bring a personal grievance case against the employer, to all companies.
• Unions will need employers' consent to access workplaces, which cannot be unreasonably withheld.
• Allowing workers to exchange holidays for cash.
