About 30 union supporters protested in Dunedin today, calling for an end to the 90-day trial law.
The protesters waved placards and flags and chanted outside the Dunedin office of Michael Woodhouse, the Minister for Workplace Relations.
A report commissioned by the Treasury recently found the government's controversial 90-day trials had not significantly increased employment.
The trial period, which came into force for small firms in 2009, then to all companies in 2011.
It allows employers to fire staff within their first 90 days of employment without giving a reason or being subject to legal action for unfair dismissal.