Grant Robertson believes Chris Luxon is confused about his own tax plan.
National's policy would lift income tax brackets to compensate for inflation and expand tax credits.
It promises to pay for the plan with about $8.4 billion worth of cuts and $6.2 billion of revenue increases, including taxing foreign buyers, which it thinks will bring in about $700 million.
Finance Minister Grant Robertson told Mike Hosking he relies on that happening every year.
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