The government has passed legislation bringing back 90-day trials for all employers.
National and ACT both campaigned on bringing the trials back for all employers, and the move was included in their coalition agreement - with a promise to introduce the legislation included in the 100-day plan.
The government said bringing the trials back would make a huge difference to the labour market and encourage businesses to hire people they otherwise might not, while the opposition argued it would take workers' rights away.
Workplace Relations and Safety Minister Brooke van Velden said passing the law under urgency was important to give employers and employees certainty about the labour market before next year.
"Retaining an employee who is a poor fit is not just costly to the business in terms of the dismissal process, but costly in terms of the whole culture of that workplace," she said on Tuesday night during the third reading.
She said the costs and risks of dismissal could lead to fewer employment opportunities for jobseekers.
Labour's Workplace Relations and Safety spokesperson Camilla Belich referred to research from Motu, commissioned by Treasury in 2016, found "no evidence that the ability to use trial periods significantly increases firms' overall hiring".
It also found "no evidence the policy increased the probability that a new hire by a firm was a disadvantaged jobseeker" and said the law did not appear to affect the likelihood of new hires remaining in the long term, or make workers less likely to move jobs.
The researchers did find a weak increase in hiring in the construction and wholesale trade industries, however.
Belich said the bill was exactly the same as the one from 2011, showing no vision, no examination of evidence, and no consideration of how New Zealand has changed since.
"The researcher who did an actual study into says it doesn't help people get jobs. So why are we extending it? Why? Why does this coalition government hate working people," she said.
While the government initially proposed sending the legislation to a select committee before Christmas, van Velden later confirmed it would instead be passed through all stages under urgency.
The 90-day trials were initially brought in by the previous National-led government, allowing workers to be dismissed within 90 days of starting work, with no need for the employer to provide a reason.
Labour had in 2017 campaigned on abolishing the law, but in coalition with New Zealand First merely limited the scheme to businesses with 19 or fewer employees.
The bill passed with the support of all three governing parties, and was opposed by all three opposition parties.