The National Party says the Government will be taking away $1000 a year off the average wage earner as a result of the upcoming budget announcements.
Instead of tax breaks, extra cash is set to be given to low income families and those with newborn babies.
Labour will lay out its family income initiative on Thursday, which is a part of the so-called "mini-budget".
National Party leader Bill English says the mini-budget will "expose a lack of money remaining in the kitty".
"Labour has created these very high expectations that everyone is going to get more of everything and between this document and the budget next year people will see that.
"Particularly with the free first year of tertiary education, which as that builds up is going to be a very expensive policy," Mr English said.
"There won't be that much money to meet the expectations they have created everywhere else, whether it is police pay rises or increased funding for NGOs."