The Labour Party has accused National of making retirement savings a political football again by planning more changes to KiwiSaver.
Finance Minister Bill English has confirmed the Budget on 19 May will include cuts to KiwiSaver incentives.
As the Government looks to get its books back into surplus as soon as possible it is looking at where it can cut its spending.
That could mean cutting the tax credits paid to people with KiwiSaver accounts, Radio New Zealand's political editor reports.
Mr English says the Government has already indicated it would make changes to Working for Families, interest-free student loans and KiwiSaver.
Labour's finance spokesperson David Cunliffe says tinkering with KiwiSaver will turn retirement savings into a political football and undermine public confidence.
But Mr English says the Government has to get its books in order to help lift national savings.