Paula Bennett has denied National is telling lies about Labour's tax plans.
National's advertising over the last couple of weeks has turned negative, almost exclusively focused on taxes it claims Labour plans to introduce - including a capital gains tax, a land tax, a regional fuel tax, new income taxes, a water tax and a fart tax.
Only two of those have any basis in what Labour has actually promised - the water levy and regional fuel tax. The water levy will be aimed at commercial users of large quantities of water, while the regional fuel tax won't be implemented centrally - instead giving Auckland Council the ability to bring one in to help pay for Auckland's growing transport costs.
Labour has ruled out any changes to income, land and capital gains taxes until after 2020, and its 'fart tax' plan is to gradually bring agriculture into the already existing emissions trading scheme.
Appearing on The AM Show on Monday, Ms Bennett was accused by host Duncan Garner of perpetuating a lie over Labour's tax plans, particularly income tax.
"It is not a lie, Duncan. I'm sorry," the Deputy Prime Minister responded.
"Everyone, or 1.3 million New Zealanders are going to be better off under National with a law that has been passed. So that is Labour will actually have to pass a law to take things away from New Zealanders."
National Party ads on social media have claimed "under Labour, income tax is going up" and "Labour confirms: You would pay $1060 more tax from 1 April".
"There is law in place now that was passed by us that says that the thresholds for income tax will be changed from April 1," says Ms Bennett. "They are going to have to pass a law to take that away, so in effect they are changing income taxes."
The same ads have also claimed Kiwis will pay "$1060 more tax with Labour". But the small print reveals that only applies to "anyone earning over $52,000". The median income in New Zealand, according to Statistics NZ, is around $49,000.
It also doesn't take into account Labour's incomes package, which includes boosts to Working for Families for families with children.
Labour MPs, including finance spokesman Grant Robertson, have called National's attacks "lies".