"This is making it more challenging for the Government to achieve its fiscal targets as quickly as it would like," he said.
Core tax revenue was $97 million below forecast due to lower than expected goods and services tax and personal income source deductions, though that was partly offset by a bigger take from corporate taxpayers and strong provisional assessments in other individuals tax.
Expenses were $118 million higher than forecast at $23.98 billion, due largely to the $103 million indemnity deed for Solid Energy to preserve the miner's balance sheet.
Prime Minister John Key last month said the new budget forecasts could show a small deficit fro the 2015 financial year, which has been a government target to get the books in black. The Treasury will update the forecasts next week at its half-year economic and fiscal update.
Today's financial statements show the residual cash deficit $57 million lower than forecast at $2.25 billion, with tax receipts from the New Zealand Superannuation Fund $308 million above expectations. That's down from $3.26 billion a year earlier.
Net debt was in line with expectations at $61.85 billion, or 27 percent of gross domestic product, while gross debt was $1.57 billion above forecast at $84.69 billion, or 37 percent of GDP.
The Crown's operating balance, which includes unrealised movements in the government's investment portfolio and actuarial valuations, was a deficit of $998 million in the four months ended Oct. 30, compared to an expected surplus of $188 million.
That was due to some $2 billion of actuarial losses from Accident Compensation Corp and Government Superannuation Fund stemming from lower interest rates. The Crown reported an operating surplus $1.83 billion a year earlier.