ACT leader David Seymour says Labour's tax policy announced yesterday picks on people who work hard.
Yesterday, Labour announced that if elected it wanted to introduce a new top tax rate of 39 per cent for income earned over $180,000.
Robertson said the proposed tax rate would affect two per cent of New Zealanders, and does not impact income earned below $180,000.
He estimated it would generate $550 million a year.
However, Seymour told TVNZ1's Breakfast this morning the policy was "purely symbolic".
"The symbolism of it is, look, we teach our kids work hard, don't pick on people. This is a policy that picks on a minority of people who work hard and the values are totally wrong."
Seymour also said it wouldn't even generate enough money anyway.
"I'm an engineer by training and your systems have to work so, fundamentally, will this policy pay off the debt? The amount of tax Labour would raise won't even cover the interest on the debt that they've borrowed," he said.
"The right thing to do is actually to reduce spending and balance the budget so we don't put the debt onto future generations."
National also criticised the move yesterday, with finance spokesperson Paul Goldsmith saying, "no country in the world has ever taxed itself out of recession, but Labour’s first instinct is to raise your taxes".
The party's leader Judith Collins repeated the sentiment, explaining: "What we don't do as a country is tax our way out of a recession.
"It's a very short-term measure."