Deputy Prime Minister Winston Peters and National leader Simon Bridges have clashed over fuel taxes in Parliament's question time today.

Mr Peters was answering questions on behalf of the absent Jacinda Ardern, who is awaiting the arrival of her first baby, and was asked by National Party leader Simon Bridges if the Prime Minister was concerned that her Government has increased the cost of living in New Zealand.

"The basis of that question is unadulterated nonsense," Mr Peters replied.

Undeterred Mr Bridges pushed on, stating the new Auckland fuel tax would increase costs to an average family by $700 a year.

"Again that is unadulterated rubbish," Mr Peters said, accusing Mr Bridges of being inconsistent after wanting to extend road infrastructure around the country himself.

Mr Bridges then suggested that the fuel tax set to be implemented in Auckland has today been legislated by Government to be applied throughout any region in New Zealand.