Fired-up National leader Simon Bridges says when it comes to the proposed Capital Gains Tax "we've got to fight it as it's an assault on the Kiwi way of life".

Speaking to Jamie Mackay on The Country, Bridges said the proposal was something Labour had been eyeing up for a long time.

"What we are going to end up with is a messy and costly swiss cheese of a tax. They don't need the money, they are pulling in an extra $18 billion over the next four years by piling on taxes, how much is enough for Grant Robertson and Jacinda Ardern."

Bridges says the tax is going to end up hurting middle-class New Zealand, instead of the super rich who Labour is targeting.

"We know Michael Cullen is about envy and ideology, and if they are really honest, Ardern and Robertson have always wanted this in the Labour Party. But this isn't going to go after the super wealthy, they can find ways of avoiding this. They can move it offshore and get the best advice.

"It is the person in Dunedin who has the rental for $350,000 who this is going to hurt. The mansion in Remuera or Parnell which is worth $4 Million won't be affected when they add in a tennis court or other extensions."

LISTEN ABOVE AS SIMON BRIDGES SPEAKS TO JAMIE MACKAY