Christopher Luxon has ruled out scrapping the top 39 percent income tax rate if elected in October.
Speaking with AM on Wednesday, the National leader said such tax relief wasn't an option in the short term.
"We may well look to do that down the road but the bottom line is New Zealand cannot afford it," Luxon told co-host Laura Tupou. "In our first term, there's just no way.
"If you look at the books and what's happening is our economic situation in New Zealand is just deteriorating and that's why, on October 14, we need a government that actually knows how to manage the economy."
But, despite this, Luxon said a National-led Government wouldn't change the top tax rate.
At the other end of the political spectrum, Labour has proposed to remove GST from fruit and vegetables; the Green Party is campaigning for a wealth tax and changes to income rates; while Te Pāti Māori wants GST off all food as well as a wealth tax and other smaller taxes.