Winston Peters accused Paula Bennett of asking "mindless questions" and diving into a "moronic abyss" during Question Time today.
His comments came as National's deputy leader was quizzing Mr Peters, who was answering on behalf of the Prime Minister, on the Employment Relations Amendment Bill in the House today.
"Can she confirm that the Labour-led Government unanimously voted for the bill at select committee and the bill has now been prepared for a second reading, and do they know how they will vote for it?" Ms Bennett asked the deputy prime minister.
"On behalf of the prime minister, if that member will not conform to the proper language of an MMP environment we do not intend to answer her mindless questions.
"She knows full well the construction, we can handle it and that's why were here and that's why they're over there, because they just don't grasp what the new environment looks like," Mr Peters answered.
Ms Bennett was then given a warning by Speaker Trevor Mallard for prefacing her follow up by implying that Mr Peters led the Government instead of Ms Ardern.
She went on to try and get more answers about the bill, asking: "Does the govt support the employment relations amendment bill as it is currently written?"
Mr Peters again went on the attack in his answer.
"Look we're not going to have a dive to the moronic abyss that the member wants to go to.
"We are talking about a process of the full committee of the House and then onto the third reading, that's whats being targeted that's what we'll do."