Loopholes wealthy people use to avoid tax are going to be closed in the budget being presented on Thursday.
Finance Minister Bill English says he's "patching up some holes in the system" to broaden the tax base. He is steering commentators away from references to austerity, saying the budget will be "pretty sensible".
Prime Minister John Key says there's going to be one or two surprises when Mr English presents the budget to parliament at 2pm "but they aren't too scary."
Mr English is expected to raise tobacco excise and give the public service new savings targets and deadlines.
The government hasn't got any spare cash and Mr English is going to deliver his second zero budget.
Ministers have already announced new spending of more than $1 billion, most of it going into health, education and welfare.
It will come from savings within those portfolios and from money shaved off the budgets of other government departments.
Liquor could also cost more from Thursday but that can't be confirmed.
Mr English told parliament on Wednesday the budget would invest significantly in infrastructure, skills and innovation.
Opposition parties are warning there will be a raft of cuts spread across departments as the government puts more money into voter-friendly areas like more operations and faster cancer treatment.
They don't think the budget is going to have anything in it to generate economic growth and create jobs.
Mr English says he has to deal with reality - debt has to be reduced and the books have to be in surplus by 2014/15 in the face of international financial uncertainty and the cost of the Christchurch earthquake.