National Party leader Simon Bridges says the $1.20 per hour increase to the minimum wage is "too far, too fast", and will impact small and medium businesses.
It was announced today that the minimum wage will increase to $17.70 per hour from the current rate of $16.50 on April 1, 2019.
The $1.20 rise is significant compared to previous years, where it generally rises between 25 to 50 cents.
"Small and medium businesses are already feeling it from industrial law changes, you add on this," Mr Bridges told media today.
"There'll be people out there that will say, 'fantastic', but it will have a real effect either in some job losses or cost of living increases for all New Zealanders.
"It effects all Kiwis right in the hip pocket."
He said the minimum wage should increase each year, "but $1.20 this year, something similar the year after" would impact businesses, the number of workers and the cost of living.
"This kind of rate, it's unsustainable when there are not productivity and other gains to go with it."
Workplace Relations Minister Iain Lees-Galloway said the April 1 increase "will benefit approximately 209,200 workers and their families, lifting wages throughout the economy by $231 million per year and making a big difference for families".