Labour acknowledged the error but said it was only included in the first version of the policy document, not the one that was sent out more widely. The error was fixed on Sunday.
National’s finance spokeswoman Nicola Willis said it was a “schoolboy error equating to a quarter-of-a-billion-dollar hole”.
The policy will take GST off fresh and frozen fruit and vegetables and is meant to kick in on April 1 next year, the first day of the tax year.
But Labour’s policy document has only costed the policy as beginning in the 2024/25 fiscal year, which begins on July 1, 2024 - three months later.
This has left the policy unfunded for three months of 2024.
The party also costed the policy for only part of the 2024/25 year, leaving it underfunded in that year.
“If the policy is introduced when promised, there will be a three-month hit to the books in the 2023/24 fiscal year, which ends in June. This is not accounted for in Labour’s policy,” Willis said.
“Labour has also made a mistake in their costing for the 2024/25 fiscal year. The annual cost of the policy should be approximately $500 million as in later years, but Labour has only budgeted $365 million. This is not explained.
“The cumulative size of this error is likely to be around $250 million over the next two years,” she said.
