The Government's books are in better shape than forecast in December 2012, but the Green Party says it is at the expense of the unemployed.
In the first seven months of the financial year, the operating deficit was $2.5 billion - nearly $600 million better than predicted.
The Treasury said spending is lower than anticipated, while the tax take is higher.
It said overall, the same amount of money was earned by fewer workers but because they were in higher paying jobs, they paid more tax.
Greens' co-leader Russel Norman said on Friday that reflects the inequality in New Zealand and the fact the Government has done nothing to deal with unemployment.
But Finance Minister Bill English said it shows that people are now earning more and working longer hours following the recession.
Mr English did concede, though, that more people in part-time work have lost their jobs.
Higher than expected tax revenues helped improve the Government's finances. The tax income was $486 million higher than the Treasury had forecast in the December half-year economic and fiscal update.
Government spending fell below expectations. As a result, the operating deficit in the seven months to the end of January was $2.5 billion - $571 million lower than forecast.
Net debt was $57.3 billion, or 27.5%, of gross domestic product.
The Government expects to return to surplus in the June 2015 financial year, but economists say that is unlikely, given a weak global recovery.
Bill English said the Government would continue to focus on keeping its finances under control.
Mr English said the Government's control of spending is reflected in the fact that in the seven months to January, spending was $282 million lower than forecast in December 2012.