The Finance Minister is still confident the Budget will get into surplus in the 2014-15 year, but Bill English warns just minor changes could jeopardise the target.
Mr English says the surplus will be very small so it would not take much to push the Government's books back into deficit.
He says the Government would not do anything drastic to ensure it reached its surplus target.
"We think it's quite important to get to surplus, very important ... as an indicator that people can have the confidence that the Government's books are under control.
"But we don't imagine significant service cuts to achieve that. I think we've shown that we are able to make progress in pretty sensible and moderate ways without cutting services to the public."
Mr English says he will release the latest Budget forecasts in the half-yearly economic and fiscal update in five weeks.