Don Brash has kicked off Te Wiki o Te Reo Māori with a "blasphemous" takedown of the haka.

"I'm going to say something which is almost blasphemous in New Zealand - I'm not sure that the haka is a good representation of who we are, and if it is, it worries me," the former National Party leader told RadioLIVE's Weekend Life show on Sunday.

"It is basically a war dance, and violence - particularly domestic violence - is one of our major headaches in New Zealand. The haka to me seems to glorify it and that often worries me."

Appearing on the show with Dr Brash was FIRST Union general secretary Robert Reid, who interrupted him.

"Oh, come on. Stop it. Stop it. Stop it right there. Don't giggle about it either. To say the haka glorifies domestic violence, to use the parliamentary term, please withdraw and apologise."

But Dr Brash, founder of lobby group Hobson's Pledge, continued.

"The haka is a war dance. It implies we're going to slaughter our opponents on the rugby field. We often draw our finger across our throat to emphases the point. I think it's overdone."