The money available for income tax cuts is shrinking as Treasury revises its forecasts of how much the Government will get from heavier taxes on property.
Under the Government's plan, increasing GST to 15% and taxing property investors more heavily will pay for cuts in income tax rates.
But Finance Minister Bill English says Treasury has a different view from the Tax Working Group on how much extra tax will be generated by changes to the way property is taxed.
Mr English says that means the trade-offs between tax changes and cuts to income tax rates will be tighter.
A member of the Tax Working Group, John Shewan, says cutting income tax still needs to be a priority.
He says a delay would be unfortunate, and the group believes personal tax cuts are a prerequisite to stronger economic growth.
