Finance Minister Steven Joyce would not be drawn on the shape of a family and tax package expected to be the centrepiece of Thursday's Budget.
But he continued to downplay expectations when he talked to reporters today at the Petone plant where the Budget is being printed.
"There is not a massive amount of room," he said.
"The amount we are in surplus is not massive compared to the overall Government investment, so I think people would be overstating it to say there is a massive amount of headroom."
Changes to Working for Families tax credits, addressing bracket-creep by raising some of the lower tax thresholds at which various tax rates kick in, and an increase in the accommodation supplement are likely areas for attention in the Budget.