The Labour Party has rejected National Party claims that its policies would cost taxpayers an extra $3 billion in 2015-16.
Costings produced by the Finance Minister Bill English's office showed the total cost of Labour's policies would rise progressively during the next five years.
But Labour's finance spokesperson David Cunliffe disputes Mr English's figures, saying National must be desperate.
"National's clearly got no policies of its own, so in desperation they've started making up falsehoods about Labour's policy. I can assure you that those numbers bear no relation whatsoever to our announced policies."
Mr Cunliffe says Labour's policies will cost an extra $500 million four years from now - not the $3 billion National claims.