Papers released to Radio New Zealand show that while the Government has suggested expanding the 90-day trial period for workers, it doesn't yet know how many are using the scheme.
The trial period was introduced in April 2009, allowing an employee in a workplace with fewer than 20 staff to be dismissed in the first 90 days, without the right to bring a personal grievance.
The Government is considering widening the scheme as part of a proposed shake-up of personal grievance laws.
Papers released under the Official Information Act show the Labour Department is conducting a survey because it knows little about the uptake of the probationary period.
Labour MP Trevor Mallard says given that that's the case, expanding the scheme makes no sense.
Labour Minister Kate Wilkinson told Morning Report there is anecdotal evidence the scheme is working, though changes are still worth considering.
Discussion document
Ms Wilkinson released the discussion document on the personal grievance process on Tuesday, saying the current law is unclear and allows parties to prolong legal proceedings.
The discussion document suggests extending the trial period beyond 90 days and allowing medium-sized businesses to take up the scheme.
It proposes setting a minimum length of time employees must work before they are eligible to take a personal grievance and setting a salary cap on their eligibility to claim a grievance.
The public has until the end of March to make submissions on the discussion document.
