The Finance Minister is promising to clamp down on people who avoid tax by setting up companies and investing in property.
Bill English says the current tax system is unfair to many working families.
He says the present system allows a family of four earning $100,000 a year to reduce their tax from $27,500 a year to less than $10,000 and there are a range of ways the family's tax burden can be cut.
Mr English says the Tax Working Group found that 10,000 households are reporting property investment losses while also claiming Working for Families tax credits and the Government will make the tax system fairer by closing this type of loophole.
The minister told Morning Report on Wednesday it is important to reinforce the integrity of the tax system and stop people from being able to effectively choose their own tax rates, making themselves eligible for specific benefits.
"You could estimate hundreds of millions, probably, from people who are in a whole lot of other ways taking the opportunity to reduce their effective tax rate. So we're not relying on some big windfall."
Mr English says the new package will be announced in the Budget in May, followed by the date it will be introduced.
